diff options
author | Christoffer Dall <christoffer.dall@arm.com> | 2019-12-12 20:50:55 +0100 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2020-05-22 21:19:29 +0100 |
commit | 6a73af05d634d774f72ea41f9518c777743726bc (patch) | |
tree | abf24a96fd7972425ca1db5a358f794bb348ea7e | |
parent | 1b0d263daed194db05df28a2a10e39fea767fcc1 (diff) | |
download | linux-stable-6a73af05d634d774f72ea41f9518c777743726bc.tar.gz |
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>
-rw-r--r-- | arch/arm/include/asm/kvm_emulate.h | 5 | ||||
-rw-r--r-- | arch/arm/include/asm/kvm_mmio.h | 2 | ||||
-rw-r--r-- | arch/arm/kvm/mmio.c | 6 | ||||
-rw-r--r-- | arch/arm64/include/asm/kvm_emulate.h | 5 | ||||
-rw-r--r-- | arch/arm64/include/asm/kvm_mmio.h | 6 |
5 files changed, 20 insertions, 4 deletions
diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h index 853e2becad18e..8d704db1ce966 100644 --- a/arch/arm/include/asm/kvm_emulate.h +++ b/arch/arm/include/asm/kvm_emulate.h @@ -105,6 +105,11 @@ static inline bool kvm_vcpu_dabt_issext(struct kvm_vcpu *vcpu) return kvm_vcpu_get_hsr(vcpu) & HSR_SSE; } +static inline bool kvm_vcpu_dabt_issf(const struct kvm_vcpu *vcpu) +{ + return false; +} + static inline int kvm_vcpu_dabt_get_rd(struct kvm_vcpu *vcpu) { return (kvm_vcpu_get_hsr(vcpu) & HSR_SRT_MASK) >> HSR_SRT_SHIFT; diff --git a/arch/arm/include/asm/kvm_mmio.h b/arch/arm/include/asm/kvm_mmio.h index adcc0d7d31757..e28cef4beae86 100644 --- a/arch/arm/include/asm/kvm_mmio.h +++ b/arch/arm/include/asm/kvm_mmio.h @@ -26,6 +26,8 @@ struct kvm_decode { unsigned long rt; bool sign_extend; + /* Not used on 32-bit arm */ + bool sixty_four; }; /* diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c index c47f108c2b8aa..c480bd438fd0f 100644 --- a/arch/arm/kvm/mmio.c +++ b/arch/arm/kvm/mmio.c @@ -112,6 +112,9 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) data = (data ^ mask) - mask; } + if (!vcpu->arch.mmio_decode.sixty_four) + data = data & 0xffffffff; + trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr, &data); data = vcpu_data_host_to_guest(vcpu, data, len); @@ -127,6 +130,7 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, unsigned long rt; int len; bool is_write, sign_extend; + bool sixty_four; if (kvm_vcpu_dabt_isextabt(vcpu)) { /* cache operation on I/O addr, tell guest unsupported */ @@ -146,6 +150,7 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, is_write = kvm_vcpu_dabt_iswrite(vcpu); sign_extend = kvm_vcpu_dabt_issext(vcpu); + sixty_four = kvm_vcpu_dabt_issf(vcpu); rt = kvm_vcpu_dabt_get_rd(vcpu); mmio->is_write = is_write; @@ -153,6 +158,7 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, mmio->len = len; vcpu->arch.mmio_decode.sign_extend = sign_extend; vcpu->arch.mmio_decode.rt = rt; + vcpu->arch.mmio_decode.sixty_four = sixty_four; /* * The MMIO instruction is emulated and should not be re-executed diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index ef490a55cdf15..9e1f3250bd739 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 fc2f689c0694e..09923122c4c95 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; }; /* |