| Message ID | 20201102191609.265711-2-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Kill the copro array | expand |
Hi Marc, On 02/11/2020 19:16, Marc Zyngier wrote: > The use of the AArch32-specific accessors have always been a bit > annoying on 64bit, and it is time for a change. > > Let's move the AArch32 exception injection over to the AArch64 encoding, > which requires us to split the two halves of FAR_EL1 into DFAR and IFAR. > This enables us to drop the preempt_disable() games on VHE, and to kill > the last user of the vcpu_cp15() macro. Hurrah! > diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c > index e2a2e48ca371..975f65ba6a8b 100644 > --- a/arch/arm64/kvm/inject_fault.c > +++ b/arch/arm64/kvm/inject_fault.c > @@ -100,39 +81,36 @@ static void inject_undef32(struct kvm_vcpu *vcpu) > * Modelled after TakeDataAbortException() and TakePrefetchAbortException > * pseudocode. > */ > -static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, > - unsigned long addr) > +static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr) > { > - u32 *far, *fsr; > - bool is_lpae; > - bool loaded; > + u64 far; > + u32 fsr; > + /* Give the guest an IMPLEMENTATION DEFINED exception */ > + if (__vcpu_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE) { With VHE, won't __vcpu_sys_reg() read the potentially stale copy in the sys_reg array? vcpu_read_sys_reg()? > + fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE; > + } else { > + /* no need to shuffle FS[4] into DFSR[10] as its 0 */ > + fsr = DFSR_FSC_EXTABT_nLPAE; > + } > > - loaded = pre_fault_synchronize(vcpu); > + far = vcpu_read_sys_reg(vcpu, FAR_EL1); Thanks, James
On 2020-11-03 18:29, James Morse wrote: > Hi Marc, > > On 02/11/2020 19:16, Marc Zyngier wrote: >> The use of the AArch32-specific accessors have always been a bit >> annoying on 64bit, and it is time for a change. >> >> Let's move the AArch32 exception injection over to the AArch64 >> encoding, >> which requires us to split the two halves of FAR_EL1 into DFAR and >> IFAR. >> This enables us to drop the preempt_disable() games on VHE, and to >> kill >> the last user of the vcpu_cp15() macro. > > Hurrah! > > >> diff --git a/arch/arm64/kvm/inject_fault.c >> b/arch/arm64/kvm/inject_fault.c >> index e2a2e48ca371..975f65ba6a8b 100644 >> --- a/arch/arm64/kvm/inject_fault.c >> +++ b/arch/arm64/kvm/inject_fault.c >> @@ -100,39 +81,36 @@ static void inject_undef32(struct kvm_vcpu *vcpu) >> * Modelled after TakeDataAbortException() and >> TakePrefetchAbortException >> * pseudocode. >> */ >> -static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, >> - unsigned long addr) >> +static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 >> addr) >> { >> - u32 *far, *fsr; >> - bool is_lpae; >> - bool loaded; >> + u64 far; >> + u32 fsr; > > >> + /* Give the guest an IMPLEMENTATION DEFINED exception */ >> + if (__vcpu_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE) { > > With VHE, won't __vcpu_sys_reg() read the potentially stale copy in > the sys_reg array? > > vcpu_read_sys_reg()? Of course you are right. Now fixed. Thanks, M.
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 7a1faf917f3c..a6778c39157d 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -561,7 +561,6 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg) #define CPx_BIAS IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) #define vcpu_cp14(v,r) ((v)->arch.ctxt.copro[(r) ^ CPx_BIAS]) -#define vcpu_cp15(v,r) ((v)->arch.ctxt.copro[(r) ^ CPx_BIAS]) struct kvm_vm_stat { ulong remote_tlb_flush; diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index e2a2e48ca371..975f65ba6a8b 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -69,26 +69,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu) #define DFSR_FSC_EXTABT_LPAE 0x10 #define DFSR_FSC_EXTABT_nLPAE 0x08 #define DFSR_LPAE BIT(9) - -static bool pre_fault_synchronize(struct kvm_vcpu *vcpu) -{ - preempt_disable(); - if (vcpu->arch.sysregs_loaded_on_cpu) { - kvm_arch_vcpu_put(vcpu); - return true; - } - - preempt_enable(); - return false; -} - -static void post_fault_synchronize(struct kvm_vcpu *vcpu, bool loaded) -{ - if (loaded) { - kvm_arch_vcpu_load(vcpu, smp_processor_id()); - preempt_enable(); - } -} +#define TTBCR_EAE BIT(31) static void inject_undef32(struct kvm_vcpu *vcpu) { @@ -100,39 +81,36 @@ static void inject_undef32(struct kvm_vcpu *vcpu) * Modelled after TakeDataAbortException() and TakePrefetchAbortException * pseudocode. */ -static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, - unsigned long addr) +static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr) { - u32 *far, *fsr; - bool is_lpae; - bool loaded; + u64 far; + u32 fsr; + + /* Give the guest an IMPLEMENTATION DEFINED exception */ + if (__vcpu_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE) { + fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE; + } else { + /* no need to shuffle FS[4] into DFSR[10] as its 0 */ + fsr = DFSR_FSC_EXTABT_nLPAE; + } - loaded = pre_fault_synchronize(vcpu); + far = vcpu_read_sys_reg(vcpu, FAR_EL1); if (is_pabt) { vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA32_IABT | KVM_ARM64_PENDING_EXCEPTION); - far = &vcpu_cp15(vcpu, c6_IFAR); - fsr = &vcpu_cp15(vcpu, c5_IFSR); + far &= GENMASK(31, 0); + far |= (u64)addr << 32; + vcpu_write_sys_reg(vcpu, fsr, IFSR32_EL2); } else { /* !iabt */ vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA32_DABT | KVM_ARM64_PENDING_EXCEPTION); - far = &vcpu_cp15(vcpu, c6_DFAR); - fsr = &vcpu_cp15(vcpu, c5_DFSR); - } - - *far = addr; - - /* Give the guest an IMPLEMENTATION DEFINED exception */ - is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31); - if (is_lpae) { - *fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE; - } else { - /* no need to shuffle FS[4] into DFSR[10] as its 0 */ - *fsr = DFSR_FSC_EXTABT_nLPAE; + far &= GENMASK(63, 32); + far |= addr; + vcpu_write_sys_reg(vcpu, fsr, ESR_EL1); } - post_fault_synchronize(vcpu, loaded); + vcpu_write_sys_reg(vcpu, far, FAR_EL1); } /**
The use of the AArch32-specific accessors have always been a bit annoying on 64bit, and it is time for a change. Let's move the AArch32 exception injection over to the AArch64 encoding, which requires us to split the two halves of FAR_EL1 into DFAR and IFAR. This enables us to drop the preempt_disable() games on VHE, and to kill the last user of the vcpu_cp15() macro. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/inject_fault.c | 62 ++++++++++--------------------- 2 files changed, 20 insertions(+), 43 deletions(-)