Commit Graph

8 Commits

Author SHA1 Message Date
David Hildenbrand
c35622387e hw/s390x/s390-skeys: lazy storage key enablement under TCG
Let's enable storage keys lazily under TCG, just as we do under KVM.
Only fairly old Linux versions actually make use of storage keys, so it
can be kind of wasteful to allocate quite some memory and track
changes and references if nobody cares.

We have to make sure to flush the TLB when enabling storage keys after
the VM was already running: otherwise it might happen that we don't
catch references or modifications afterwards.

Add proper documentation to all callbacks.

The kvm-unit-tests skey tests keeps on working with this change.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210903155514.44772-14-david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-09-06 16:24:05 +02:00
David Hildenbrand
390191c6f6 s390x/mmu_helper: move address validation into mmu_translate*()
Let's move address validation into mmu_translate() and
mmu_translate_real(). This allows for checking whether an absolute
address is valid before looking up the storage key. We can now get rid of
the ram_size check.

Interestingly, we're already handling LOAD REAL ADDRESS wrong, because
a) We're not supposed to touch storage keys
b) We're not supposed to convert to an absolute address

Let's use a fake, negative MMUAccessType to teach mmu_translate() to
fix that handling and to not perform address validation.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210903155514.44772-8-david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-09-06 16:24:05 +02:00
David Hildenbrand
eaa0feea75 s390x/tcg: check for addressing exceptions for RRBE, SSKE and ISKE
Let's replace the ram_size check by a proper physical address space
check (for example, to prepare for memory hotplug), trigger addressing
exceptions and trace the return value of the storage key getter/setter.

Provide an helper mmu_absolute_addr_valid() to be used in other context
soon. Always test for "read" instead of "write" as we are not actually
modifying the page itself.

Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210903155514.44772-5-david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-09-06 16:24:05 +02:00
David Hildenbrand
06d8a10a70 s390x/tcg: convert real to absolute address for RRBE, SSKE and ISKE
For RRBE, SSKE, and ISKE, we're dealing with real addresses, so we have to
convert to an absolute address first.

In the future, when adding EDAT1 support, we'll have to pay attention to
SSKE handling, as we'll be dealing with absolute addresses when the
multiple-block control is one.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210903155514.44772-4-david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-09-06 16:24:05 +02:00
David Hildenbrand
fe00c705fe s390x/tcg: fix ignoring bit 63 when setting the storage key in SSKE
Right now we could set an 8-bit storage key via SSKE and retrieve it
again via ISKE, which is against the architecture description:

SSKE:
"
The new seven-bit storage-key value, or selected bits
thereof, is obtained from bit positions 56-62 of gen-
eral register R 1 . The contents of bit positions 0-55
and 63 of the register are ignored.
"

ISKE:
"
The seven-bit storage key is inserted in bit positions
56-62 of general register R 1 , and bit 63 is set to zero.
"

Let's properly ignore bit 63 to create the correct seven-bit storage key.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210903155514.44772-3-david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-09-06 16:24:05 +02:00
David Hildenbrand
634a0b51cb s390x/tcg: wrap address for RRBE
Let's wrap the address just like for SSKE and ISKE.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210903155514.44772-2-david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-09-06 16:24:04 +02:00
Richard Henderson
be9568b4e0 tcg: Rename helper_atomic_*_mmu and provide for user-only
Always provide the atomic interface using TCGMemOpIdx oi
and uintptr_t retaddr.  Rename from helper_* to cpu_* so
as to (mostly) match the exec/cpu_ldst.h functions, and
to emphasize that they are not callable from TCG directly.

Tested-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-21 07:45:38 -10:00
Cho, Yu-Chen
c9274b6bf0 target/s390x: start moving TCG-only code to tcg/
move everything related to translate, as well as HELPER code in tcg/

mmu_helper.c stays put for now, as it contains both TCG and KVM code.

After the reshuffling, update MAINTAINERS accordingly.
Make use of the new directory:

target/s390x/tcg/

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Cho, Yu-Chen <acho@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210707105324.23400-8-acho@suse.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2021-07-07 14:01:56 +02:00