Commit Graph

45510 Commits

Author SHA1 Message Date
Sergey Fedorov
90aa39a1cc tcg: Allow goto_tb to any target PC in user mode
In user mode, there's only a static address translation, TBs are always
invalidated properly and direct jumps are reset when mapping change.
Thus the destination address is always valid for direct jumps and
there's no need to restrict it to the pages the TB resides in.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Blue Swirl <blauwirbel@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:42 -10:00
Sergey Fedorov
5b053a4a28 tcg: Clean up direct block chaining safety checks
We don't take care of direct jumps when address mapping changes. Thus we
must be sure to generate direct jumps so that they always keep valid
even if address mapping changes. Luckily, we can only allow to execute a
TB if it was generated from the pages which match with current mapping.

Document tcg_gen_goto_tb() declaration and note the reason for
destination PC limitations.

Some targets with variable length instructions allow TB to straddle a
page boundary. However, we make sure that both of TB pages match the
current address mapping when looking up TBs. So it is safe to do direct
jumps into the both pages. Correct the checks for some of those targets.

Given that, we can safely patch a TB which spans two pages. Remove the
unnecessary check in cpu_exec() and allow such TBs to be patched.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
f9c5b66f48 tcg: Clean up tb_jmp_unlink()
Unify the code of this function with tb_jmp_remove_from_list(). Making
these functions similar improves their readability. Also this could be a
step towards making this function thread-safe.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
89bba49632 tcg: Extract removing of jumps to TB from tb_phys_invalidate()
Move the code for removing jumps to a TB out of tb_phys_invalidate() to
a separate static inline function tb_jmp_unlink(). This simplifies
tb_phys_invalidate() and improves code structure.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
133626783a tcg: Rename tb_jmp_remove() to tb_remove_from_jmp_list()
tb_jmp_remove() was only used to remove the TB from a list of all TBs
jumping to the same TB which is n-th jump destination of the given TB.
Put a comment briefly describing the function behavior and rename it to
better reflect its purpose.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
9962c478b1 tcg: Clarify thread safety check in tb_add_jump()
The check is to make sure that another thread hasn't already done the
same while we were outside of tb_lock. Mention this in a comment.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
901bc3deb4 tcg: Init TB's direct jumps before making it visible
Initialize TB's direct jump list data fields and reset the jumps before
tb_link_page() puts it into the physical hash table and the physical
page list. So TB is completely initialized before it becomes visible.

This is pure rearrangement of code to a more suitable place, though it
could be a preparation for relaxing the locking scheme in future.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
e90d96b158 tcg: Rearrange tb_link_page() to avoid forward declaration
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
c37e6d7e35 tcg: Use uintptr_t type for jmp_list_{next|first} fields of TB
These fields do not contain pure pointers to a TranslationBlock
structure. So uintptr_t is the most appropriate type for them.
Also put some asserts to assure that the two least significant bits of
the pointer are always zero before assigning it to jmp_list_first.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
f309101c26 tcg: Clean up direct block chaining data fields
Briefly describe in a comment how direct block chaining is done. It
should help in understanding of the following data fields.

Rename some fields in TranslationBlock and TCGContext structures to
better reflect their purpose (dropping excessive 'tb_' prefix in
TranslationBlock but keeping it in TCGContext):
   tb_next_offset  =>  jmp_reset_offset
   tb_jmp_offset   =>  jmp_insn_offset
   tb_next         =>  jmp_target_addr
   jmp_next        =>  jmp_list_next
   jmp_first       =>  jmp_list_first

Avoid using a magic constant as an invalid offset which is used to
indicate that there's no n-th jump generated.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Richard Henderson
7ba6a512ae translate-all: Adjust 256mb testing for mips64
Make sure we preserve the high 32-bits when masking for mips64.

Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Emilio G. Cota
8bdf499782 translate-all: add missing munmap of the code_gen guard page for MIPS
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1461283314-2353-2-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Emilio G. Cota
835154b6e2 translate-all: remove redundant setting of tcg_ctx.code_gen_buffer_size
The setting of tcg_ctx.code_gen_buffer_size is done by the only caller of
size_code_gen_buffer(), which is code_gen_alloc():

  $ git grep size_code_gen_buffer
  translate-all.c:static inline size_t size_code_gen_buffer(size_t tb_size)
  translate-all.c:    tcg_ctx.code_gen_buffer_size = size_code_gen_buffer(tb_size);

Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1461283314-2353-1-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
10b4f48555 tcg: Note requirement on atomic direct jump patching
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1461341333-19646-12-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
c82460a560 tcg/mips: Make direct jump patching thread-safe
Ensure direct jump patching in MIPS is atomic by using
atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-11-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
[rth: Merged the deposit32 followup.]
[rth: Merged the following followup.]
Message-Id: <1462210518-26522-1-git-send-email-sergey.fedorov@linaro.org>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
84f79fb7c6 tcg/sparc: Make direct jump patching thread-safe
Ensure direct jump patching in SPARC is atomic by using
atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1461341333-19646-10-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
9e26911295 tcg/aarch64: Make direct jump patching thread-safe
Ensure direct jump patching in AArch64 is atomic by using
atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-9-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
7d14e0e2d6 tcg/arm: Make direct jump patching thread-safe
Ensure direct jump patching in ARM is atomic by using
atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-8-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
ed3d51ecd7 tcg/s390: Make direct jump patching thread-safe
Ensure direct jump patching in s390 is atomic by:
 * naturally aligning a location of direct jump address;
 * using atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-7-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
0d07abf05e tcg/i386: Make direct jump patching thread-safe
Ensure direct jump patching in i386 is atomic by:
 * naturally aligning a location of direct jump address;
 * using atomic_read()/atomic_set() for code patching.

tcg_out_nopn() implementation:
Suggested-by: Richard Henderson <rth@twiddle.net>.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-6-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
399f164857 tcg/ppc: Make direct jump patching thread-safe
Ensure direct jump patching in PPC is atomic by:
 * limiting translation buffer size in 32-bit mode to be addressable by
   Branch I-form instruction;
 * using atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1461341333-19646-5-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:40 -10:00
Sergey Fedorov
76442a939e tci: Make direct jump patching thread-safe
Ensure direct jump patching in TCI is atomic by:
 * naturally aligning a location of direct jump address;
 * using atomic_read()/atomic_set() to load/store the address.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-4-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:40 -10:00
Sergey Fedorov
6b587d3cda include/qemu/osdep.h: Add macros for pointer alignment
These macros provide a convenient way to n-byte align pointers up and
down and check if a pointer is n-byte aligned.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-3-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:40 -10:00
Sergey Fedorov
18a60a7614 include/qemu/osdep.h: Add a macro to check for alignment
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-2-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:40 -10:00
Emilio G. Cota
89fee74a0f tb: consistently use uint32_t for tb->flags
We are inconsistent with the type of tb->flags: usage varies loosely
between int and uint64_t. Settle to uint32_t everywhere, which is
superior to both: at least one target (aarch64) uses the most significant
bit in the u32, and uint64_t is wasteful.

Compile-tested for all targets.

Suggested-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Suggested-by: Richard Henderson <rth@twiddle.net>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1460049562-23517-1-git-send-email-cota@braap.org>
2016-05-12 14:06:40 -10:00
Peter Maydell
f68419eee9 Block layer patches
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABAgAGBQJXNIcBAAoJEH8JsnLIjy/WiUQP/Rzfo8pe7TWA2InxdcDOPsx4
 2/tHHJdVkffnNX5rdBvc0mOUZNJxej0NtJu2e63BB+ydYju//xw8gruKU7TR+Nd3
 nPNSsqk80prK3RNgWu7qymBvIkHDDcDQhlp48HKq+dxrfConXtHmoXapGsqc0S47
 xu03oC6WzSIyLf7TLytcjUmEprQSaCGOwsb/XaHAWL750fFAGcdy/K5PWBpUv6DN
 T0jZ3u4UneE1jeabRmqAwjgDJXC9l6riH9fP/ZtYhgNlNj84zlMXajUHSULhGknP
 cTGjwwg9tOvhcjTdhdRmWlvG1m0T77ZX3icfZLhcTdb/Uz68NXVqs8P25IGV9McD
 DPrb3T/M8JUoqLXJxIpxUm2Levof5v0dUF1PHmN5bT7pshcqv/1J7v8Fdtf9l9mp
 zI0+FK1TZ102C0H2F7AWYZSlo2EfNUSd02QQx6MbfDokDIlIxY+EgP1/Es5XlkqC
 wc7HrJvq+uix2zXw9bn9Vg9p/nDuxlRx+ppRRarNNRonaqTrx/1qAaas4bsqc9Gz
 H6gxw7BHybm0TZFdHqAdIonpesecYw6yWUXT/mQehbfphsmQmu/d2HvF2C9uUm4X
 O0JduBlKOTm2hMcg5qL6Gko8WaQIctdCJH/1Onts92cZnm8Vr/9zcmMgwGoCd7sE
 +t6Yg0jqpTUJwhZhIuCw
 =NbjJ
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Thu 12 May 2016 14:37:05 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (69 commits)
  qemu-iotests: iotests: fail hard if not run via "check"
  block: enable testing of LUKS driver with block I/O tests
  block: add support for encryption secrets in block I/O tests
  block: add support for --image-opts in block I/O tests
  qemu-io: Add 'write -z -u' to test MAY_UNMAP flag
  qemu-io: Add 'write -f' to test FUA flag
  qemu-io: Allow unaligned access by default
  qemu-io: Use bool for command line flags
  qemu-io: Make 'open' subcommand more like command line
  qemu-io: Add missing option documentation
  qmp: add monitor command to add/remove a child
  quorum: implement bdrv_add_child() and bdrv_del_child()
  Add new block driver interface to add/delete a BDS's child
  qemu-img: check block status of backing file when converting.
  iotests: fix the redirection order in 083
  block: Inactivate all children
  block: Drop superfluous invalidating bs->file from drivers
  block: Invalidate all children
  nbd: Simplify client FUA handling
  block: Honor BDRV_REQ_FUA during write_zeroes
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-05-12 16:33:40 +01:00
Peter Maydell
e4f70d6358 target-arm queue:
* blizzard, omap_lcdc: code cleanup to remove DEPTH != 32 dead code
  * QOMify various ARM devices
  * bcm2835_property: use cached values when querying framebuffer
  * hw/arm/nseries: don't allocate large sized array on the stack
  * fix LPAE descriptor address masking (only visible for EL2)
  * fix stage 2 exec permission handling for AArch32
  * first part of supporting syndrome info for data aborts to EL2
  * virt: NUMA support
  * work towards i.MX6 support
  * avoid unnecessary TLB flush on TCR_EL2, TCR_EL3 writes
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABCAAGBQJXNIUqAAoJEDwlJe0UNgzeYmMP/05g/rzOekjL4c41MvN8zUrB
 z8CFRmySbTNda/gyY/o8DDUvJOq637g1Arw82o3jYJBTVx/EjFTK4ENe7zN99Xay
 fzzUtOp+TY40k9ZUQ3FtdAiN/Y54WHuozX3CKOu47W7hErkNn4/GVG68IW93AHe7
 AIxVDUrNUCsMPGFy0YBOTWM5u9kwrosH6vb+EvBSDXJTrdALidf0CWBGp58Ik79g
 T3dAKE9EuVTWVKnR3J6QTxD97Xmvsj/2dVtNOGXRw7ZL/utmtCG/uO1V06VMmf8R
 5LPY56RemhhF4CftYnk9+kzdftFJKt2kHsmfoEHSfsrhpp51Ro9/3WnFGstOjjQL
 OUFwpmHKpaINRTs6zudMTiUoI3JtzNI7cefSWuu0+O8ErLnqxfJEQgnZStUpi/JG
 V/YAoEiA+ZYTv8gm3X7a6+cb+g/DiqLlPorpE4xFFR4gbzIujjAsFQMmsqlTisNl
 j0yjflQAcUCTgo9wzoi5DxHZ69OfpZXL6gAU4HKhTum+w0436WyPLtVxD7bCxe71
 ki0Mol61Hh62p0swUkBv9YHNOj2PKghQwVFTOtxtUs4jPfOTItg795A/cDJGXGe8
 zcAUNdwnKp/OsbaVMEOirko02qlS+F3FaOcg/qAchDgCZcOliUlSQTKoNnMyKMhC
 PjQVUfYpU/59r+ESJ6OL
 =RL/g
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20160512' into staging

target-arm queue:
 * blizzard, omap_lcdc: code cleanup to remove DEPTH != 32 dead code
 * QOMify various ARM devices
 * bcm2835_property: use cached values when querying framebuffer
 * hw/arm/nseries: don't allocate large sized array on the stack
 * fix LPAE descriptor address masking (only visible for EL2)
 * fix stage 2 exec permission handling for AArch32
 * first part of supporting syndrome info for data aborts to EL2
 * virt: NUMA support
 * work towards i.MX6 support
 * avoid unnecessary TLB flush on TCR_EL2, TCR_EL3 writes

# gpg: Signature made Thu 12 May 2016 14:29:14 BST using RSA key ID 14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"

* remotes/pmaydell/tags/pull-target-arm-20160512: (43 commits)
  hw/arm: QOM'ify versatilepb.c
  hw/arm: QOM'ify strongarm.c
  hw/arm: QOM'ify stellaris.c
  hw/arm: QOM'ify spitz.c
  hw/arm: QOM'ify pxa2xx_pic.c
  hw/arm: QOM'ify pxa2xx.c
  hw/arm: QOM'ify integratorcp.c
  hw/arm: QOM'ify highbank.c
  hw/arm: QOM'ify armv7m.c
  target-arm: Avoid unnecessary TLB flush on TCR_EL2, TCR_EL3 writes
  hw/display/blizzard: Remove blizzard_template.h
  hw/display/blizzard: Expand out macros
  i.MX: Add sabrelite i.MX6 emulation.
  i.MX: Add i.MX6 SOC implementation.
  i.MX: Add the Freescale SPI Controller
  FIFO: Add a FIFO32 implementation
  i.MX: Add i.MX6 System Reset Controller device.
  ARM: Factor out ARM on/off PSCI control functions
  ACPI: Virt: Generate SRAT table
  ACPI: move acpi_build_srat_memory to common place
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-05-12 15:55:45 +01:00
Peter Maydell
6ddeeffffe QAPI patches for 2016-05-12
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJXNDVwAAoJEDhwtADrkYZTMgUP/2lm5d7rrbk25x/vOvbah2Mu
 I6CrQsNN7RLqNrq2v/wHSdraiKhwIaIkpgiJqaznEIawbGWrd8alV7Ae1AoPh7Ng
 fObNKTlmaWD7OJxFvXDnJZueB+XLjeVE4cWEJ+aAN/THaDDeXm1WfbvcVAtJnsnj
 wdzt0kJze+Waj2lYcn2pC2WrgCksufE7ye/P/ouVXh8yPFG74j5RkEaGgU1YYG57
 Mc1cjTlI4IpEE4AdtZj7W96ozKk8DbQG6rR64lY2t2xFf4DOTGnPvDxbFRtqk/K8
 WZ9CQ2ZEWvxJ2VFQGWcE6UK2U1uilBGrLeGFDuxJcz3b6ShytqQ0kVeZ2o0uuPof
 wH/23XrB3p8ZuTbSLBUtMPw0FjHKbgBHLOE/18xHA7G0rZiKUISpNzClNo939S7g
 sbKvohSMLLei6GZ++eBAHotSa7bI48Vw0dXuXlI0GEEQmZpRkxLywQsJRBJ+Qw1V
 VdqW667BV4Opof93YGAeUSeioJ51v+usGG2qF/5IKPHI3NVbj8FIqc4hMZgek+2j
 aukYdDOha7Ml3FHfkHet5nNMrx59mI1+wnRe/KDjSxRZKdlB2G/6L8TWgaDV9MJj
 qeytuOvyu/TC7UI9kere+DLy9PeyTXoeKmWqyxBGEZv5DO1XkBPam/tIob8e7x9r
 Dx8iCThc7FwlZrWRof/h
 =1WHk
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-05-12' into staging

QAPI patches for 2016-05-12

# gpg: Signature made Thu 12 May 2016 08:49:04 BST using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2016-05-12: (23 commits)
  qapi: Change visit_type_FOO() to no longer return partial objects
  qapi: Simplify semantics of visit_next_list()
  qapi: Fix string input visitor handling of invalid list
  tests/string-input-visitor: Add negative integer tests
  qapi: Split visit_end_struct() into pieces
  qmp: Tighten output visitor rules
  qmp: Don't reuse qmp visitor after grabbing output
  spapr_drc: Expose 'null' in qom-get when there is no fdt
  qmp: Support explicit null during visits
  qapi: Add visit_type_null() visitor
  tests: Add check-qnull
  qapi: Document visitor interfaces, add assertions
  qmp-input: Refactor when list is advanced
  qmp-input: Require struct push to visit members of top dict
  qom: Wrap prop visit in visit_start_struct
  qapi-commands: Wrap argument visit in visit_start_struct
  qmp-input: Don't consume input when checking has_member
  qapi: Use strict QMP input visitor in more places
  qapi: Consolidate QMP input visitor creation
  qmp-input: Clean up stack handling
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-05-12 15:06:38 +01:00
Kevin Wolf
efc2645f71 Block patches for 2.7
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQEcBAABCAAGBQJXNIZVAAoJEDuxQgLoOKytrQcH/1PleLZ6jzu1ZQLmrCx73OBf
 B8pLjSNvGxGQaFfc0SZi4kLhsVtk5s7CZwwY2i0xSnYetcrOa/w9ioLj4j9CkSpb
 zU80k+HeYagLGpF5TbVbMaBcZK0UAu0ti4eWGcbwN5rdpmO4sdpTrR5rx8n0dziW
 qj20p7Z9NfDPEQfMJ45Aco0cQ//NsAh4FaPCHdJvgIsrL7uoD9dQ6CN+DrstXQsq
 GRSS/doWCxohtdX01C5OLATvTKkEO10hrO9INo27Db/XC0PovaELZTa5lfQgYBlD
 zx4Xv2ga/dEf3pYWTj2/wPmBa06GUV3xts3WpWJqjbXkYbczWllYoqA4z7R0/lw=
 =A6+m
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'mreitz/tags/pull-block-for-kevin-2016-05-12' into queue-block

Block patches for 2.7

# gpg: Signature made Thu May 12 15:34:13 2016 CEST using RSA key ID E838ACAD
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"

* mreitz/tags/pull-block-for-kevin-2016-05-12:
  qemu-iotests: iotests: fail hard if not run via "check"
  block: enable testing of LUKS driver with block I/O tests
  block: add support for encryption secrets in block I/O tests
  block: add support for --image-opts in block I/O tests
  qemu-io: Add 'write -z -u' to test MAY_UNMAP flag
  qemu-io: Add 'write -f' to test FUA flag
  qemu-io: Allow unaligned access by default
  qemu-io: Use bool for command line flags
  qemu-io: Make 'open' subcommand more like command line
  qemu-io: Add missing option documentation
  qmp: add monitor command to add/remove a child
  quorum: implement bdrv_add_child() and bdrv_del_child()
  Add new block driver interface to add/delete a BDS's child
  qemu-img: check block status of backing file when converting.
  iotests: fix the redirection order in 083

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:35:20 +02:00
Peter Maydell
f83b70f701 usb: misc fixes
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABAgAGBQJXMxUBAAoJEEy22O7T6HE4R+sQALnPiINyxgh0TccX0PXlj8SB
 Tou19B1F+Jyxu7UEUpvxxaTnc15xLCvp1b1aHTGkbzdoFBElVEnEYBIlpRZeGggg
 bmyJLvKZ5tFt29e+Vqd/laCt0VmICBaq6gyytInJw8JyhK7TWY6RnZAnrT+Q/wbG
 lQ1a4WN+VeVkNB+U7Kq1bhxUWlt4ljRW6gD/8J2itO+OENx1eOcUsqYTd8EcVIV3
 LNWo12NFoXID5QTgdWWZVOjY+umB1OmJlIlIkttELgi1p1u8q+Fti0BydI0f/CHk
 ncfJ+mx5AFcbBSam3EnzlY9/N5oDNQLBKX5aKgMYtI9P+fbHad7mAVKk/cAuxM4U
 2kcTvI7faIKwdiNC9afk08CFkaZwMTfysWPMji1fVT0qyMxClp30eYxEffgxTY6o
 9zUfKvLlYydqypTaotpDkst3PoPi5GZvuVysxpFIAgVUryXRFgNUXZidM8k3nQGj
 E/yjMyOcF/mqno7Qgj2kUfLVRGCT+/v1ehOTWpo2fuzwJX4FPINGNOb3TdnJZ+5g
 zRRPM6jPPrJbO5IMWBZvF4wpKdcyNul+vpmEYkP4AKqPX9KdSE12cDNYdw04uNT7
 oWc5wPkozhgHzQxzeAG5ce9dHm+akcY4M6O7SK1UaF4R9N1mJRmrGvDpoS7MwDAe
 698ui4T1hGJXWzu3WrGd
 =KS11
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/kraxel/tags/pull-usb-20160511-1' into staging

usb: misc fixes

# gpg: Signature made Wed 11 May 2016 12:18:25 BST using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-usb-20160511-1:
  usb: Support compilation without poll.h
  usb-mtp: fix usb_mtp_get_device_info so that libmtp on the guest doesn't complain
  usb:xhci: no DMA on HC reset

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-05-12 14:34:35 +01:00
Sascha Silbe
5a8fabf333 qemu-iotests: iotests: fail hard if not run via "check"
Running an iotests-based Python test directly might appear to work,
but may fail in subtle ways and is insecure:

- It creates files with predictable file names in a world-writable
  location (/var/tmp).

- Tests expect the environment to be set up by check. E.g. 041 and 055
  may take the wrong code paths if QEMU_DEFAULT_MACHINE is not
  set. This can lead to false negatives.

Instead fail hard and tell the user we want to be run via "check".

The actual environment expected by the tests is currently only defined
by the implementation of "check". We use two of the environment
variables set by "check" as indication of whether we're being run via
"check". Anyone writing their own test runner (replacing "check") will
need to replicate the full environment (in a broader sense, not just
environment variables) provided by "check" anyway, including setting
the two environment variables we check. Whereas a regular developer
just trying to invoke the tests usually won't have both of these
defined in their environment so we can catch their mistake and give
out useful advice.

Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Reviewed-by: Bo Tu <tubo@linux.vnet.ibm.com>
Message-id: 1461094442-16014-1-git-send-email-silbe@linux.vnet.ibm.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Daniel P. Berrange
4e9b25fb05 block: enable testing of LUKS driver with block I/O tests
This adds support for testing the LUKS driver with the block
I/O test framework.

   cd tests/qemu-io-tests
   ./check -luks

A handful of test cases are modified to work with luks

 - 004 - whitelist luks format
 - 012 - use TEST_IMG_FILE instead of TEST_IMG for file ops
 - 048 - use TEST_IMG_FILE instead of TEST_IMG for file ops.
         don't assume extended image contents is all zeros,
         explicitly initialize with zeros
         Make file size smaller to avoid having to decrypt
         1 GB of data.
 - 052 - don't assume initial image contents is all zeros,
         explicitly initialize with zeros
 - 100 - don't assume initial image contents is all zeros,
         explicitly initialize with zeros

With this patch applied, the results are as follows:

  Passed: 001 002 003 004 005 008 009 010 011 012 021 032 043
          047 048 049 052 087 100 134 143
  Failed: 033 120 140 145
 Skipped: 007 013 014 015 017 018 019 020 022 023 024 025 026
          027 028 029 030 031 034 035 036 037 038 039 040 041
          042 043 044 045 046 047 049 050 051 053 054 055 056
          057 058 059 060 061 062 063 064 065 066 067 068 069
          070 071 072 073 074 075 076 077 078 079 080 081 082
          083 084 085 086 087 088 089 090 091 092 093 094 095
          096 097 098 099 101 102 103 104 105 107 108 109 110
          111 112 113 114 115 116 117 118 119 121 122 123 124
          128 129 130 131 132 133 134 135 136 137 138 139 141
          142 144 146 148 150 152

The reasons for the failed tests are:

 - 033 - needs adapting to use image opts syntax with blkdebug
         and test image in order to correctly set align property
 - 120 - needs adapting to use correct -drive syntax for luks
 - 140 - needs adapting to use correct -drive syntax for luks
 - 145 - needs adapting to use correct -drive syntax for luks

The vast majority of skipped tests are exercising code that is
qcow2 specific, though a couple could probably be usefully
enabled for luks too.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1462896689-18450-4-git-send-email-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Daniel P. Berrange
b7e875b2f9 block: add support for encryption secrets in block I/O tests
The LUKS block driver tests will require the ability to specify
encryption secrets with block devices. This requires using the
--object argument to qemu-img/qemu-io to create a 'secret'
object.

When the IMGKEYSECRET env variable is set, it provides the
password to be associated with a secret called 'keysec0'

The _qemu_img_wrapper function isn't modified as that needs
to cope with differing syntax for subcommands, so can't be
made to use the image opts syntax unconditionally.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1462896689-18450-3-git-send-email-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Daniel P. Berrange
076003f526 block: add support for --image-opts in block I/O tests
Currently all block tests use the traditional syntax for images
just specifying a filename. To support the LUKS driver without
resorting to JSON, the tests need to be able to use the new
--image-opts argument to qemu-img and qemu-io.

This introduces a new env variable IMGOPTSSYNTAX. If this is
set to 'true', then qemu-img/qemu-io should use --image-opts.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1462896689-18450-2-git-send-email-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Eric Blake
c2e001cc82 qemu-io: Add 'write -z -u' to test MAY_UNMAP flag
Make it easier to control whether the BDRV_REQ_MAY_UNMAP flag
can be passed through a write_zeroes command, by adding the '-u'
flag to qemu-io 'write -z' and 'aio_write -z'.  To be useful,
the device has to be opened with BDRV_O_UNMAP (done by default
in qemu-io, but can be made explicit with '-d unmap').

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1462677405-4752-7-git-send-email-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Eric Blake
770e0e0e80 qemu-io: Add 'write -f' to test FUA flag
Make it easier to test block drivers with BDRV_REQ_FUA in
.supported_write_flags, by adding the '-f' flag to qemu-io to
conditionally pass the flag through to specific writes ('write',
'write -z', 'writev', 'aio_write', 'aio_write -z'). You'll want
to use 'qemu-io -t none' to actually make -f useful (as
otherwise, the default writethrough mode automatically sets the
FUA bit on every write).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1462677405-4752-6-git-send-email-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Eric Blake
093ea232b0 qemu-io: Allow unaligned access by default
There's no reason to require the user to specify a flag just so
they can pass in unaligned numbers.  Keep 'read -p' and 'write -p'
as no-ops so that I don't have to hunt down and update all users
of qemu-io, but otherwise make their behavior default as 'read' and
'write'.  Also fix 'write -z', 'readv', 'writev', 'writev',
'aio_read', 'aio_write', and 'aio_write -z'.  For now, 'read -b',
'write -b', and 'write -c' still require alignment (and 'multiwrite',
but that's slated to die soon).

qemu-iotest 23 is updated to match, as the only test that was
previously explicitly expecting an error on an unaligned request.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1462677405-4752-5-git-send-email-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Eric Blake
dc38852aaa qemu-io: Use bool for command line flags
We require a C99 compiler; let's use it to express what we
really mean.

(Yes, we now have an instance of 'if (bool + bool + bool > 1)',
which, although semantically valid C, looks ugly; it gets
cleaned up later.)

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1462677405-4752-4-git-send-email-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Eric Blake
b8d970f1a9 qemu-io: Make 'open' subcommand more like command line
The command line defaults to BDRV_O_UNMAP, but can use
-d to reset it.  Meanwhile, the 'open' subcommand was
defaulting to no discards, with no way to set it.

The command line has both -n and -tMODE to set a variety
of cache modes, but the 'open' subcommand had only -n.

The 'open' subcommand had no way to set BDRV_O_NATIVE_AIO.

Note that the 'reopen' subcommand uses '-c' where the
command line and 'open' use -t.  Making that consistent
would be a separate patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1462677405-4752-3-git-send-email-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:24 +02:00
Eric Blake
e4e12bb26d qemu-io: Add missing option documentation
The Usage: summary is missing several options, but rather than
having to maintain it, it's simpler to just state [OPTIONS],
since the options are spelled out below.

Commit 499afa2 added --image-opts, but forgot to document it in
--help.  Likewise for commit 9e8f183 and -d/--discard.

Commit e3aff4f6 put "-o/--offset" in the long opts, but it has
never been honored.

Add a note that '-n' is short for '-t none'.

Commit 9a2d77ad killed the -C option, but forgot to undocument
it for the 'open' subcommand.

Finally, commit 10d9d75 removed -g/--growable, but forgot to
cull it from the valid short options.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1462677405-4752-2-git-send-email-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Wen Congyang
7f82159769 qmp: add monitor command to add/remove a child
The new QMP command name is x-blockdev-change. It's just for adding/removing
quorum's child now, and doesn't support all kinds of children, all kinds of
operations, nor all block drivers. So it is experimental now.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1462865799-19402-4-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Wen Congyang
98292c61bc quorum: implement bdrv_add_child() and bdrv_del_child()
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Message-id: 1462865799-19402-3-git-send-email-xiecl.fnst@cn.fujitsu.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Wen Congyang
e06018ad28 Add new block driver interface to add/delete a BDS's child
In some cases, we want to take a quorum child offline, and take
another child online.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1462865799-19402-2-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Ren Kimura
263a6f4c3a qemu-img: check block status of backing file when converting.
When converting images, check the block status of its backing file chain
to avoid needlessly reading zeros.

Signed-off-by: Ren Kimura <rkx1209dev@gmail.com>
Message-id: 1461773098-20356-1-git-send-email-rkx1209dev@gmail.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Wei Jiangang
9036e87c74 iotests: fix the redirection order in 083
It should redirect stdout to /dev/null first,
then redirect stderr to whatever stdout currently points at.

Signed-off-by: Wei Jiangang <weijg.fnst@cn.fujitsu.com>
Message-id: 1461665601-14908-1-git-send-email-weijg.fnst@cn.fujitsu.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Fam Zheng
aad0b7a0bf block: Inactivate all children
Currently we only inactivate the top BDS. Actually bdrv_inactivate
should be the opposite of bdrv_invalidate_cache.

Recurse into the whole subtree instead.

Because a node may have multiple parents, and because once
BDRV_O_INACTIVE is set for a node, further writes are not allowed, we
cannot interleave flag settings and .bdrv_inactivate calls (that may
submit write to other nodes in a graph) within a single pass. Therefore
two passes are used here.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00
Fam Zheng
c9e9e9c66c block: Drop superfluous invalidating bs->file from drivers
Now they are invalidated by the block layer, so it's not necessary to
do this in block drivers' implementations of .bdrv_invalidate_cache.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00
Fam Zheng
0d1c5c9160 block: Invalidate all children
Currently we only recurse to bs->file, which will miss the children in quorum
and VMDK.

Recurse into the whole subtree to avoid that.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00
Eric Blake
52a4650574 nbd: Simplify client FUA handling
Now that the block layer honors per-bds FUA support, we don't
have to duplicate the fallback flush at the NBD layer.  The
static function nbd_co_writev_flags() is no longer needed, and
the driver can just directly use nbd_client_co_writev().

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00
Eric Blake
465fe887cc block: Honor BDRV_REQ_FUA during write_zeroes
The block layer has a couple of cases where it can lose
Force Unit Access semantics when writing a large block of
zeroes, such that the request returns before the zeroes
have been guaranteed to land on underlying media.

SCSI does not support FUA during WRITESAME(10/16); FUA is only
supported if it falls back to WRITE(10/16).  But where the
underlying device is new enough to not need a fallback, it
means that any upper layer request with FUA semantics was
silently ignoring BDRV_REQ_FUA.

Conversely, NBD has situations where it can support FUA but not
ZERO_WRITE; when that happens, the generic block layer fallback
to bdrv_driver_pwritev() (or the older bdrv_co_writev() in qemu
2.6) was losing the FUA flag.

The problem of losing flags unrelated to ZERO_WRITE has been
latent in bdrv_co_do_write_zeroes() since commit aa7bfbff, but
back then, it did not matter because there was no FUA flag.  It
became observable when commit 93f5e6d8 paved the way for flags
that can impact correctness, when we should have been using
bdrv_co_writev_flags() with modified flags.  Compare to commit
9eeb6dd, which got flag manipulation right in
bdrv_co_do_zero_pwritev().

Symptoms: I tested with qemu-io with default writethrough cache
(which is supposed to use FUA semantics on every write), and
targetted an NBD client connected to a server that intentionally
did not advertise NBD_FLAG_SEND_FUA.  When doing 'write 0 512',
the NBD client sent two operations (NBD_CMD_WRITE then
NBD_CMD_FLUSH) to get the fallback FUA semantics; but when doing
'write -z 0 512', the NBD client sent only NBD_CMD_WRITE.

The fix is do to a cleanup bdrv_co_flush() at the end of the
operation if any step in the middle relied on a BDS that does
not natively support FUA for that step (note that we don't
need to flush after every operation, if the operation is broken
into chunks based on bounce-buffer sizing).  Each BDS gains a
new flag .supported_zero_flags, which parallels the use of
.supported_write_flags but only when accessing a zero write
operation (the flags MUST be different, because of SCSI having
different semantics based on WRITE vs. WRITESAME; and also
because BDRV_REQ_MAY_UNMAP only makes sense on zero writes).

Also fix some documentation to describe -ENOTSUP semantics,
particularly since iscsi depends on those semantics.

Down the road, we may want to add a driver where its
.bdrv_co_pwritev() honors all three of BDRV_REQ_FUA,
BDRV_REQ_ZERO_WRITE, and BDRV_REQ_MAY_UNMAP, and advertise
this via bs->supported_write_flags for blocks opened by that
driver; such a driver should NOT supply .bdrv_co_write_zeroes
nor .supported_zero_flags.  But none of the drivers touched
in this patch want to do that (the act of writing zeroes is
different enough from normal writes to deserve a second
callback).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00