Hi Marc, On Sat, May 28, 2022 at 12:49 PM Marc Zyngier <maz@xxxxxxxxxx> wrote: > > We really don't want PENDING_EXCEPTION and INCREMENT_PC to ever be > set at the same time, as they are mutually exclusive. Add checks > that will generate a warning should this ever happen. > > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> > --- > arch/arm64/include/asm/kvm_emulate.h | 1 + > arch/arm64/kvm/hyp/nvhe/sys_regs.c | 2 ++ > arch/arm64/kvm/inject_fault.c | 8 ++++++++ > 3 files changed, 11 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h > index 46e631cd8d9e..861fa0b24a7f 100644 > --- a/arch/arm64/include/asm/kvm_emulate.h > +++ b/arch/arm64/include/asm/kvm_emulate.h > @@ -473,6 +473,7 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu, > > static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu) > { > + WARN_ON(vcpu_get_flag(vcpu, PENDING_EXCEPTION)); > vcpu_set_flag(vcpu, INCREMENT_PC); > } > > diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c > index 2841a2d447a1..04973984b6db 100644 > --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c > +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c > @@ -38,6 +38,8 @@ static void inject_undef64(struct kvm_vcpu *vcpu) > *vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR); > *vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR); > > + WARN_ON(vcpu_get_flag(vcpu, INCREMENT_PC)); > + > vcpu_set_flag(vcpu, PENDING_EXCEPTION); > vcpu_set_flag(vcpu, EXCEPT_AA64_EL1_SYNC); > > diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c > index a9a7b513f3b0..2f4b9afc16ec 100644 > --- a/arch/arm64/kvm/inject_fault.c > +++ b/arch/arm64/kvm/inject_fault.c > @@ -20,6 +20,8 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr > bool is_aarch32 = vcpu_mode_is_32bit(vcpu); > u32 esr = 0; > > + WARN_ON(vcpu_get_flag(vcpu, INCREMENT_PC)); > + Minor nit: While we're at it, should we just create a helper for setting PENDING_EXCEPTION, same as we have for INCREMENT_PC? That might make the code clearer and save us from the hassle of having this WARN_ON before every instance of setting PENDING_EXCEPTION? Cheers, /fuad > vcpu_set_flag(vcpu, PENDING_EXCEPTION); > vcpu_set_flag(vcpu, EXCEPT_AA64_EL1_SYNC); > > @@ -51,6 +53,8 @@ static void inject_undef64(struct kvm_vcpu *vcpu) > { > u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); > > + WARN_ON(vcpu_get_flag(vcpu, INCREMENT_PC)); > + > vcpu_set_flag(vcpu, PENDING_EXCEPTION); > vcpu_set_flag(vcpu, EXCEPT_AA64_EL1_SYNC); > > @@ -71,6 +75,8 @@ static void inject_undef64(struct kvm_vcpu *vcpu) > > static void inject_undef32(struct kvm_vcpu *vcpu) > { > + WARN_ON(vcpu_get_flag(vcpu, INCREMENT_PC)); > + > vcpu_set_flag(vcpu, PENDING_EXCEPTION); > vcpu_set_flag(vcpu, EXCEPT_AA32_UND); > } > @@ -94,6 +100,8 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr) > > far = vcpu_read_sys_reg(vcpu, FAR_EL1); > > + WARN_ON(vcpu_get_flag(vcpu, INCREMENT_PC)); > + > if (is_pabt) { > vcpu_set_flag(vcpu, PENDING_EXCEPTION); > vcpu_set_flag(vcpu, EXCEPT_AA32_IABT); > -- > 2.34.1 >