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| author |   Steven Price <steven.price@arm.com> | 2021-06-21 12:17:15 +0100 |
|---|---|---|
| committer |   Marc Zyngier <maz@kernel.org> | 2021-06-22 14:08:06 +0100 |
| commit | f0376edb1ddcab19a473b4bf1fbd5b6bbed3705b (patch) | |
| tree | 34470ac344cda4f7e8353e0b1392c089bbb3123e /arch/arm64/include/asm/mte-def.h | |
| parent | KVM: arm64: Expose KVM_ARM_CAP_MTE (diff) | |
| download | linux-dev-f0376edb1ddcab19a473b4bf1fbd5b6bbed3705b.tar.xz linux-dev-f0376edb1ddcab19a473b4bf1fbd5b6bbed3705b.zip | |
KVM: arm64: Add ioctl to fetch/store tags in a guest
The VMM may not wish to have it's own mapping of guest memory mapped
with PROT_MTE because this causes problems if the VMM has tag checking
enabled (the guest controls the tags in physical RAM and it's unlikely
the tags are correct for the VMM).
Instead add a new ioctl which allows the VMM to easily read/write the
tags from guest memory, allowing the VMM's mapping to be non-PROT_MTE
while the VMM can still read/write the tags for the purpose of
migration.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210621111716.37157-6-steven.price@arm.com
Diffstat (limited to 'arch/arm64/include/asm/mte-def.h')
| -rw-r--r-- | arch/arm64/include/asm/mte-def.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mte-def.h b/arch/arm64/include/asm/mte-def.h index cf241b0f0a42..626d359b396e 100644 --- a/arch/arm64/include/asm/mte-def.h +++ b/arch/arm64/include/asm/mte-def.h @@ -7,6 +7,7 @@ #define MTE_GRANULE_SIZE UL(16) #define MTE_GRANULE_MASK (~(MTE_GRANULE_SIZE - 1)) +#define MTE_GRANULES_PER_PAGE (PAGE_SIZE / MTE_GRANULE_SIZE) #define MTE_TAG_SHIFT 56 #define MTE_TAG_SIZE 4 #define MTE_TAG_MASK GENMASK((MTE_TAG_SHIFT + (MTE_TAG_SIZE - 1)), MTE_TAG_SHIFT) |