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authorChristoffer Dall <christoffer.dall@arm.com>2019-12-12 20:50:55 +0100
committerBen Hutchings <ben@decadent.org.uk>2020-05-22 21:19:29 +0100
commit6a73af05d634d774f72ea41f9518c777743726bc (patch)
treeabf24a96fd7972425ca1db5a358f794bb348ea7e /arch/arm64
parent1b0d263daed194db05df28a2a10e39fea767fcc1 (diff)
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KVM: arm64: Only sign-extend MMIO up to register width
commit b6ae256afd32f96bec0117175b329d0dd617655e upstream. 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> Link: https://lore.kernel.org/r/20191212195055.5541-1-christoffer.dall@arm.com [bwh: Backported to 3.16: - Use ESR_EL2_SF - Adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/kvm_emulate.h5
-rw-r--r--arch/arm64/include/asm/kvm_mmio.h6
2 files changed, 7 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index ef490a55cdf1..9e1f3250bd73 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -140,6 +140,11 @@ static inline bool kvm_vcpu_dabt_issext(const struct kvm_vcpu *vcpu)
return !!(kvm_vcpu_get_hsr(vcpu) & ESR_EL2_SSE);
}
+static inline bool kvm_vcpu_dabt_issf(const struct kvm_vcpu *vcpu)
+{
+ return !!(kvm_vcpu_get_hsr(vcpu) & ESR_EL2_SF);
+}
+
static inline int kvm_vcpu_dabt_get_rd(const struct kvm_vcpu *vcpu)
{
return (kvm_vcpu_get_hsr(vcpu) & ESR_EL2_SRT_MASK) >> ESR_EL2_SRT_SHIFT;
diff --git a/arch/arm64/include/asm/kvm_mmio.h b/arch/arm64/include/asm/kvm_mmio.h
index fc2f689c0694..09923122c4c9 100644
--- a/arch/arm64/include/asm/kvm_mmio.h
+++ b/arch/arm64/include/asm/kvm_mmio.h
@@ -22,13 +22,11 @@
#include <asm/kvm_asm.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;
};
/*