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author | Christoffer Dall <christoffer.dall@arm.com> | 2019-12-12 20:50:55 +0100 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2020-01-19 16:05:10 +0000 |
commit | b6ae256afd32f96bec0117175b329d0dd617655e (patch) | |
tree | 1bc03d09b49e89f9b00e8664bc9cb19eb3ac6bff /arch/arm64/include/asm/kvm_mmio.h | |
parent | Linux 5.5-rc4 (diff) | |
download | linux-dev-b6ae256afd32f96bec0117175b329d0dd617655e.tar.xz linux-dev-b6ae256afd32f96bec0117175b329d0dd617655e.zip |
KVM: arm64: Only sign-extend MMIO up to register width
On AArch64 you can do a sign-extended load to either a 32-bit or 64-bit
register, and we should only sign extend the register up to the width of
the register as specified in the operation (by using the 32-bit Wn or
64-bit Xn register specifier).
As it turns out, the architecture provides this decoding information in
the SF ("Sixty-Four" -- how cute...) bit.
Let's take advantage of this with the usual 32-bit/64-bit header file
dance and do the right thing on AArch64 hosts.
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191212195055.5541-1-christoffer.dall@arm.com
Diffstat (limited to 'arch/arm64/include/asm/kvm_mmio.h')
-rw-r--r-- | arch/arm64/include/asm/kvm_mmio.h | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/kvm_mmio.h b/arch/arm64/include/asm/kvm_mmio.h index 02b5c48fd467..b204501a0c39 100644 --- a/arch/arm64/include/asm/kvm_mmio.h +++ b/arch/arm64/include/asm/kvm_mmio.h @@ -10,13 +10,11 @@ #include <linux/kvm_host.h> #include <asm/kvm_arm.h> -/* - * This is annoying. The mmio code requires this, even if we don't - * need any decoding. To be fixed. - */ struct kvm_decode { unsigned long rt; bool sign_extend; + /* Witdth of the register accessed by the faulting instruction is 64-bits */ + bool sixty_four; }; void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data); |