We found a case where the source passed to flatview_write_continue() may
overlap with the destination when fuzzing igb, a new proposed network
device with sanitizers.
igb uses pci_dma_map() to get Tx packet, and pci_dma_write() to write Rx
buffer. While pci_dma_write() is usually used to write data from
memory not mapped to the guest, if igb is configured to perform
loopback, the data will be sourced from the guest memory. The source and
destination can overlap and the usage of memcpy() will be invalid in
such a case.
While we do not really have to deal with such an invalid request for
igb, detecting the overlap in igb code beforehand requires complex code,
and only covers this specific case. Instead, just replace memcpy() with
memmove() to tolerate overlaps. Using memmove() will slightly damage the
performance as it will need to check overlaps before using SIMD
instructions for copying, but the cost should be negligible, considering
the inherent complexity of flatview_write_continue().
The test cases generated by the fuzzer is available at:
https://patchew.org/QEMU/20230129053316.1071513-1-alxndr@bu.edu/
The fixed test case is:
fuzz/crash_47dfe62d9f911bf523ff48cd441b61c0013ed805
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Acked-by: Alexander Bulekov <alxndr@bu.edu>
Acked-by: David Hildenbrand <david@redhat.com>
Message-Id: <20230131030155.18932-1-akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The watchpoint API is specific to TCG system emulation.
Move it to a new compile unit. The inlined stubs are used
for user-mode and non-TCG accelerators.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221209141254.68662-1-philmd@linaro.org>
We have two inclusion loops:
block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h
block/block.h
-> block/block-io.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h
I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac.
Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
The 'hwaddr' type is defined in "exec/hwaddr.h" as:
hwaddr is the type of a physical address
(its size can be different from 'target_ulong').
All definitions use the 'HWADDR_' prefix, except TARGET_FMT_plx:
$ fgrep define include/exec/hwaddr.h
#define HWADDR_H
#define HWADDR_BITS 64
#define HWADDR_MAX UINT64_MAX
#define TARGET_FMT_plx "%016" PRIx64
^^^^^^
#define HWADDR_PRId PRId64
#define HWADDR_PRIi PRIi64
#define HWADDR_PRIo PRIo64
#define HWADDR_PRIu PRIu64
#define HWADDR_PRIx PRIx64
#define HWADDR_PRIX PRIX64
Since hwaddr's size can be *different* from target_ulong, it is
very confusing to read one of its format using the 'TARGET_FMT_'
prefix, normally used for the target_long / target_ulong types:
$ fgrep TARGET_FMT_ include/exec/cpu-defs.h
#define TARGET_FMT_lx "%08x"
#define TARGET_FMT_ld "%d"
#define TARGET_FMT_lu "%u"
#define TARGET_FMT_lx "%016" PRIx64
#define TARGET_FMT_ld "%" PRId64
#define TARGET_FMT_lu "%" PRIu64
Apparently this format was missed during commit a8170e5e97
("Rename target_phys_addr_t to hwaddr"), so complete it by
doing a bulk-rename with:
$ sed -i -e s/TARGET_FMT_plx/HWADDR_FMT_plx/g $(git grep -l TARGET_FMT_plx)
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230110212947.34557-1-philmd@linaro.org>
[thuth: Fix some warnings from checkpatch.pl along the way]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Tweak the semantic patch to drop redundant parenthesis around the
return expression.
Coccinelle drops a comment in hw/rdma/vmw/pvrdma_cmd.c; restored
manually.
Coccinelle messes up vmdk_co_create(), not sure why. Change dropped,
will be done manually in the next commit.
Line breaks in target/avr/cpu.h and hw/rdma/vmw/pvrdma_cmd.c tidied up
manually.
Whitespace in tools/virtiofsd/fuse_lowlevel.c tidied up manually.
checkpatch.pl complains "return of an errno should typically be -ve"
two times for hw/9pfs/9p-synth.c. Preexisting, the patch merely makes
it visible to checkpatch.pl.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221122134917.1217307-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add a function to get the file descriptor for a RAMBlock. Device
emulation code typically uses the MemoryRegion APIs but vhost-style code
may use RAMBlock directly for sharing guest memory with another process.
This new API will be used by the libblkio block driver so it can share
guest memory via .bdrv_register_buf().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20221013185908.1297568-11-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The base qemu_ram_addr_from_host function is already in
softmmu/physmem.c; move the nofail version to be adjacent.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Now that host_memory_backend_pagesize() is not depending on the hugetlb
memory path handling anymore, we can also remove the #ifdef and the
TOCTTOU comment from the calling functions - the code should now work
equally well on all host architectures.
Message-Id: <20220810125720.3849835-3-thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The bug is an uninitialized memory read, along the translate_fail
path, which results in garbage being read from iotlb_to_section,
which can lead to a crash in io_readx/io_writex.
The bug may be fixed by writing any value with zero
in ~TARGET_PAGE_MASK, so that the call to iotlb_to_section using
the xlat'ed address returns io_mem_unassigned, as desired by the
translate_fail path.
It is most useful to record the original physical page address,
which will eventually be logged by memory_region_access_valid
when the access is rejected by unassigned_mem_accepts.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1065
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220621153829.366423-1-richard.henderson@linaro.org>
Determine the BARs used by the PCI device and register handlers to
manage the access to the same.
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 3373e10b5be5f42846f0632d4382466e1698c505.1655151679.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Since the implementation unit is page-vary.c.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-24-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.
This avoids the need for a constructor initialization too.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add the 'memory' bit to the memory attributes to restrict bus
controller accesses to memories.
Introduce flatview_access_allowed() to check bus permission
before running any bus transaction.
Have read/write accessors return MEMTX_ACCESS_ERROR if an access is
restricted.
There is no change for the default case where 'memory' is not set.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211215182421.418374-4-philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[thuth: Replaced MEMTX_BUS_ERROR with MEMTX_ACCESS_ERROR, remove "inline"]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Remove unuseful local 'result' variables.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211215182421.418374-3-philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
* cleanups of qemu_oom_check() and qemu_memalign()
* target/arm/translate-neon: UNDEF if VLD1/VST1 stride bits are non-zero
* target/arm/translate-neon: Simplify align field check for VLD3
* GICv3 ITS: add more trace events
* GICv3 ITS: implement 8-byte accesses properly
* GICv3: fix minor issues with some trace/log messages
* ui/cocoa: Use the standard about panel
* target/arm: Provide cpu property for controling FEAT_LPA2
* hw/arm/virt: Disable LPA2 for -machine virt-6.2
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Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20220307' into staging
target-arm queue:
* cleanups of qemu_oom_check() and qemu_memalign()
* target/arm/translate-neon: UNDEF if VLD1/VST1 stride bits are non-zero
* target/arm/translate-neon: Simplify align field check for VLD3
* GICv3 ITS: add more trace events
* GICv3 ITS: implement 8-byte accesses properly
* GICv3: fix minor issues with some trace/log messages
* ui/cocoa: Use the standard about panel
* target/arm: Provide cpu property for controling FEAT_LPA2
* hw/arm/virt: Disable LPA2 for -machine virt-6.2
# gpg: Signature made Mon 07 Mar 2022 16:46:06 GMT
# gpg: using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg: issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg: aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg: aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83 15CF 3C25 25ED 1436 0CDE
* remotes/pmaydell/tags/pull-target-arm-20220307:
hw/arm/virt: Disable LPA2 for -machine virt-6.2
target/arm: Provide cpu property for controling FEAT_LPA2
ui/cocoa: Use the standard about panel
hw/intc/arm_gicv3_cpuif: Fix register names in ICV_HPPIR read trace event
hw/intc/arm_gicv3: Fix missing spaces in error log messages
hw/intc/arm_gicv3: Specify valid and impl in MemoryRegionOps
hw/intc/arm_gicv3_its: Add trace events for table reads and writes
hw/intc/arm_gicv3_its: Add trace events for commands
target/arm/translate-neon: Simplify align field check for VLD3
target/arm/translate-neon: UNDEF if VLD1/VST1 stride bits are non-zero
osdep: Move memalign-related functions to their own header
util: Put qemu_vfree() in memalign.c
util: Use meson checks for valloc() and memalign() presence
util: Share qemu_try_memalign() implementation between POSIX and Windows
meson.build: Don't misdetect posix_memalign() on Windows
util: Return valid allocation for qemu_try_memalign() with zero size
util: Unify implementations of qemu_memalign()
util: Make qemu_oom_check() a static function
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Move the various memalign-related functions out of osdep.h and into
their own header, which we include only where they are used.
While we're doing this, add some brief documentation comments.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20220226180723.1706285-10-peter.maydell@linaro.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-14-f4bug@amsat.org>
cpu_memory_rw_debug() is declared in "exec/cpu-all.h" which
contains target-specific declarations. To be able to use it
from target agnostic source, move the declaration to the
generic "exec/cpu-common.h" header.
Replace the target-specific 'target_ulong' type by 'vaddr'
which better reflects the argument type, and is target agnostic.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-5-f4bug@amsat.org>
The function qemu_madvise() and the QEMU_MADV_* constants associated
with it are used in only 10 files. Move them out of osdep.h to a new
qemu/madvise.h header that is included where it is needed.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220208200856.3558249-2-peter.maydell@linaro.org
dma_memory_set() does a DMA barrier, set the address space with
a constant value. The constant value filling code is not specific
to DMA and can be used for AddressSpace. Extract it as a new
helper: address_space_set().
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[lv: rebase]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220115203725.3834712-2-laurent@vivier.eu>
When we set cpu->cflags_next_tb it is because we want to carefully
control the execution of the next TB. Currently there is a race that
causes the second stage of watchpoint handling to get ignored if an
IRQ is processed before we finish executing the instruction that
triggers the watchpoint. Use the new CF_NOIRQ facility to avoid the
race.
We also suppress IRQs when handling precise self modifying code to
avoid unnecessary bouncing.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/245
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211129140932.4115115-3-alex.bennee@linaro.org>
This is a counterpart to the HMP "info ramblock" command. It is being
added with an "x-" prefix because this QMP command is intended as an
adhoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Watchpoints that should fire after the memory access
break an execution of the current block, try to
translate current instruction into the separate block,
which then causes debug interrupt.
But cpu_interrupt can't be called in such block when
icount is enabled, because interrupts muse be allowed
explicitly.
This patch sets CF_LAST_IO flag for retranslated block,
allowing interrupt request for the last instruction.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <163542169727.2127597.8141772572696627329.stgit@pasha-ThinkPad-X280>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
cpu_check_watchpoint function checks cpu->watchpoint_hit at the entry.
But then it also does the same in the middle of the function,
while this field can't change.
That is why this patch removes this useless condition.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <163542169094.2127597.8801843697434113110.stgit@pasha-ThinkPad-X280>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Watchpoint processing code restores vCPU state twice:
in tb_check_watchpoint and in cpu_loop_exit_restore/cpu_restore_state.
Normally it does not affect anything, but in icount mode instruction
counter is incremented twice and becomes incorrect.
This patch eliminates unneeded CPU state restore.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <163542168516.2127597.8781375223437124644.stgit@pasha-ThinkPad-X280>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Fix the comment to match what the code is doing, as explained in
the changelog of commit 86cf9e1546
that introduced the change:
Commit 9458a9a1df added synchronization
of vCPU and migration operations through calling run_on_cpu operation.
However, in replay mode this synchronization is unneeded, because
I/O and vCPU threads are already synchronized.
This patch disables such synchronization for record/replay mode.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <163429018454.1146856.3429437540871060739.stgit@bahia.huguette>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Provide a name field for all the memory listeners. It can be used to identify
which memory listener is which.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210817013553.30584-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a new RAMBlock flag to denote "protected" memory, i.e. memory that
looks and acts like RAM but is inaccessible via normal mechanisms,
including DMA. Use the flag to skip protected memory regions when
mapping RAM for DMA in VFIO.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The realpath() function can return NULL on error, so we need to check
for it to avoid crashing when we try to strstr() into it.
This can happen if we run out of memory, or if /sys/ is not mounted,
among other situations.
Fixes: Coverity 1459913, 1460474
Fixes: ce317be98d ("exec: fetch the alignment of Linux devdax pmem character device nodes")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Jingqi Liu <jingqi.liu@intel.com>
Message-id: 20210812151525.31456-1-peter.maydell@linaro.org
In the alignment check added to qemu_ram_alloc_from_fd() in commit
ce317be98d, the condition includes a check that 'mr' is not
NULL. This check is unnecessary because we can assume that the
caller always passes us a valid MemoryRegion, and indeed later in the
function we assume mr is not NULL when we pass it to file_ram_alloc()
as new_block->mr. Remove it.
Fixes: Coverity 1459867
Fixes: ce317be98d ("exec: fetch the alignment of Linux devdax pmem character device nodes")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Jingqi Liu <jingqi.liu@intel.com>
Message-id: 20210812150624.29139-1-peter.maydell@linaro.org
When adding RAM_NORESERVE, we forgot to remove the old assertion when
adding the updated one, most probably when reworking the patches or
rebasing. We can easily crash QEMU by adding
-object memory-backend-ram,id=mem0,size=500G,reserve=off
to the QEMU cmdline:
qemu-system-x86_64: ../softmmu/physmem.c:2146: qemu_ram_alloc_internal:
Assertion `(ram_flags & ~(RAM_SHARED | RAM_RESIZEABLE | RAM_PREALLOC))
== 0' failed.
Fix it by removing the old assertion.
Fixes: 8dbe22c686 ("memory: Introduce RAM_NORESERVE and wire it up in qemu_ram_mmap()")
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-id: 20210805092350.31195-1-david@redhat.com
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We want to separate the two cases whereby we discard ram
- uncoordinated: e.g., virito-balloon
- coordinated: e.g., virtio-mem coordinated via the RamDiscardManager
Reviewed-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210413095531.25603-12-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
We have users in migration context that don't hold the BQL (when
finishing migration). To prepare for further changes, use a dedicated mutex
instead of atomic operations. Keep using qatomic_read ("READ_ONCE") for the
functions that only extract the current state (e.g., used by
virtio-balloon), locking isn't necessary.
While at it, split up the counter into two variables to make it easier
to understand.
Suggested-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210413095531.25603-11-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Let's support RAM_NORESERVE via MAP_NORESERVE on Linux. The flag has no
effect on most shared mappings - except for hugetlbfs and anonymous memory.
Linux man page:
"MAP_NORESERVE: Do not reserve swap space for this mapping. When swap
space is reserved, one has the guarantee that it is possible to modify
the mapping. When swap space is not reserved one might get SIGSEGV
upon a write if no physical memory is available. See also the discussion
of the file /proc/sys/vm/overcommit_memory in proc(5). In kernels before
2.6, this flag had effect only for private writable mappings."
Note that the "guarantee" part is wrong with memory overcommit in Linux.
Also, in Linux hugetlbfs is treated differently - we configure reservation
of huge pages from the pool, not reservation of swap space (huge pages
cannot be swapped).
The rough behavior is [1]:
a) !Hugetlbfs:
1) Without MAP_NORESERVE *or* with memory overcommit under Linux
disabled ("/proc/sys/vm/overcommit_memory == 2"), the following
accounting/reservation happens:
For a file backed map
SHARED or READ-only - 0 cost (the file is the map not swap)
PRIVATE WRITABLE - size of mapping per instance
For an anonymous or /dev/zero map
SHARED - size of mapping
PRIVATE READ-only - 0 cost (but of little use)
PRIVATE WRITABLE - size of mapping per instance
2) With MAP_NORESERVE, no accounting/reservation happens.
b) Hugetlbfs:
1) Without MAP_NORESERVE, huge pages are reserved.
2) With MAP_NORESERVE, no huge pages are reserved.
Note: With "/proc/sys/vm/overcommit_memory == 0", we were already able
to configure it for !hugetlbfs globally; this toggle now allows
configuring it more fine-grained, not for the whole system.
The target use case is virtio-mem, which dynamically exposes memory
inside a large, sparse memory area to the VM.
[1] https://www.kernel.org/doc/Documentation/vm/overcommit-accounting
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-10-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's introduce RAM_NORESERVE, allowing mmap'ing with MAP_NORESERVE. The
new flag has the following semantics:
"
RAM is mmap-ed with MAP_NORESERVE. When set, reserving swap space (or huge
pages if applicable) is skipped: will bail out if not supported. When not
set, the OS will do the reservation, if supported for the memory type.
"
Allow passing it into:
- memory_region_init_ram_nomigrate()
- memory_region_init_resizeable_ram()
- memory_region_init_ram_from_file()
... and teach qemu_ram_mmap() and qemu_anon_ram_alloc() about the flag.
Bail out if the flag is not supported, which is the case right now for
both, POSIX and win32. We will add Linux support next and allow specifying
RAM_NORESERVE via memory backends.
The target use case is virtio-mem, which dynamically exposes memory
inside a large, sparse memory area to the VM.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-9-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's pass flags instead of bools to prepare for passing other flags and
update the documentation of qemu_ram_mmap(). Introduce new QEMU_MAP_
flags that abstract the mmap() PROT_ and MAP_ flag handling and simplify
it.
We expose only flags that are currently supported by qemu_ram_mmap().
Maybe, we'll see qemu_mmap() in the future as well that can implement these
flags.
Note: We don't use MAP_ flags as some flags (e.g., MAP_SYNC) are only
defined for some systems and we want to always be able to identify
these flags reliably inside qemu_ram_mmap() -- for example, to properly
warn when some future flags are not available or effective on a system.
Also, this way we can simplify PROT_ handling as well.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-8-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's pass ram_flags to qemu_ram_alloc() and qemu_ram_alloc_internal(),
preparing for passing additional flags.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-7-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
RAM_SHARED now also properly indicates shared anonymous memory. Let's check
that flag for anonymous memory as well, to restore the proper mapping.
Fixes: 06329ccecf ("mem: add share parameter to memory-backend-ram")
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210406080126.24010-4-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We can create shared anonymous memory via
"-object memory-backend-ram,share=on,..."
which is, for example, required by PVRDMA for mremap() to work.
Shared anonymous memory is weird, though. Instead of MADV_DONTNEED, we
have to use MADV_REMOVE: MADV_DONTNEED will only remove / zap all
relevant page table entries of the current process, the backend storage
will not get removed, resulting in no reduced memory consumption and
a repopulation of previous content on next access.
Shared anonymous memory is internally really just shmem, but without a
fd exposed. As we cannot use fallocate() without the fd to discard the
backing storage, MADV_REMOVE gets the same job done without a fd as
documented in "man 2 madvise". Removing backing storage implicitly
invalidates all page table entries with relevant mappings - an additional
MADV_DONTNEED is not required.
Fixes: 06329ccecf ("mem: add share parameter to memory-backend-ram")
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210406080126.24010-3-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's drop the "shared" parameter from ram_block_add() and properly
store it in the flags of the ram block instead, such that
qemu_ram_is_shared() properly succeeds on all ram blocks that were mapped
MAP_SHARED.
We'll use this information next to fix some cases with shared anonymous
memory.
Reviewed-by: Igor Kotrasinski <i.kotrasinsk@partner.samsung.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210406080126.24010-2-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch enables reverse debugging with watchpoints.
Reverse continue scans the execution to find the breakpoints
and watchpoints that should fire. It uses helper function
replay_breakpoint() for that. But this function needs to access
icount, which can't be correct in the middle of TB.
Therefore, in case of watchpoint, we have to retranslate the block
to allow this access.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <162072430303.827403.7379783546934958566.stgit@pasha-ThinkPad-X280>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We want to make use of ram_block_discard_range() in the RAM block resize
callback when growing a RAM block, *before* used_length is changed.
Let's relax the check. As RAM blocks always mmap the whole max_length area,
we cannot corrupt unrelated data.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210429112708.12291-6-david@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Resizing while migrating is dangerous and does not work as expected.
The whole migration code works on the usable_length of ram blocks and does
not expect this to change at random points in time.
In the case of precopy, the ram block size must not change on the source,
after syncing the RAM block list in ram_save_setup(), so as long as the
guest is still running on the source.
Resizing can be trigger *after* (but not during) a reset in
ACPI code by the guest
- hw/arm/virt-acpi-build.c:acpi_ram_update()
- hw/i386/acpi-build.c:acpi_ram_update()
Use the ram block notifier to get notified about resizes. Let's simply
cancel migration and indicate the reason. We'll continue running on the
source. No harm done.
Update the documentation. Postcopy will be handled separately.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210429112708.12291-5-david@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Manual merge
Ram block notifiers are currently not aware of resizes. To properly
handle resizes during migration, we want to teach ram block notifiers about
resizeable ram.
Introduce the basic infrastructure but keep using max_size in the
existing notifiers. Supply the max_size when adding and removing ram
blocks. Also, notify on resizes.
Acked-by: Paul Durrant <paul@xen.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: xen-devel@lists.xenproject.org
Cc: haxm-team@intel.com
Cc: Paul Durrant <paul@xen.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Wenchao Wang <wenchao.wang@intel.com>
Cc: Colin Xu <colin.xu@intel.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210429112708.12291-3-david@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Factor it out into common code when a new notifier is registered, just
as done with the memory region notifier. This keeps logic about how to
process existing ram blocks at a central place.
Just like when adding a new ram block, we have to register the max_length.
Ram blocks are only "fake resized". All memory (max_length) is mapped.
Print the warning from inside qemu_vfio_ram_block_added().
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210429112708.12291-2-david@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Stop including exec/address-spaces.h in files that don't need it.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-5-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Stop including cpu.h in files that don't need it.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-4-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Stop including sysemu/sysemu.h in files that don't need it.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-2-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
