| Message ID | 20240321155356.3236459-5-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM/arm64: Add NV support for ERET and PAuth | expand |
On Thu, Mar 21, 2024 at 03:53:45PM +0000, Marc Zyngier wrote: > It has become obvious that HCR_EL2.NV serves the exact same use > as VCPU_HYP_CONTEXT, only in an architectural way. So just drop > the flag for good. > > Reviewed-by: Joey Gouly <joey.gouly@arm.com> > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > arch/arm64/include/asm/kvm_host.h | 2 -- > arch/arm64/kvm/hyp/vhe/switch.c | 7 +------ > 2 files changed, 1 insertion(+), 8 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 839c76529bb2..3f1c3c91e5c2 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -816,8 +816,6 @@ struct kvm_vcpu_arch { > #define DEBUG_STATE_SAVE_SPE __vcpu_single_flag(iflags, BIT(5)) > /* Save TRBE context if active */ > #define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6)) > -/* vcpu running in HYP context */ > -#define VCPU_HYP_CONTEXT __vcpu_single_flag(iflags, BIT(7)) > > /* SVE enabled for host EL0 */ > #define HOST_SVE_ENABLED __vcpu_single_flag(sflags, BIT(0)) > diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c > index 1581df6aec87..58415783fd53 100644 > --- a/arch/arm64/kvm/hyp/vhe/switch.c > +++ b/arch/arm64/kvm/hyp/vhe/switch.c > @@ -197,7 +197,7 @@ static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) > * If we were in HYP context on entry, adjust the PSTATE view > * so that the usual helpers work correctly. > */ > - if (unlikely(vcpu_get_flag(vcpu, VCPU_HYP_CONTEXT))) { > + if (unlikely(read_sysreg(hcr_el2) & HCR_NV)) { Can this be additionally predicated on vcpu_has_nv() so we condition on the NV cpucap and avoid the sysreg read on non-nesting hardware?
On Tue, 16 Apr 2024 21:06:26 +0100, Oliver Upton <oliver.upton@linux.dev> wrote: > > On Thu, Mar 21, 2024 at 03:53:45PM +0000, Marc Zyngier wrote: > > diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c > > index 1581df6aec87..58415783fd53 100644 > > --- a/arch/arm64/kvm/hyp/vhe/switch.c > > +++ b/arch/arm64/kvm/hyp/vhe/switch.c > > @@ -197,7 +197,7 @@ static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) > > * If we were in HYP context on entry, adjust the PSTATE view > > * so that the usual helpers work correctly. > > */ > > - if (unlikely(vcpu_get_flag(vcpu, VCPU_HYP_CONTEXT))) { > > + if (unlikely(read_sysreg(hcr_el2) & HCR_NV)) { > > Can this be additionally predicated on vcpu_has_nv() so we condition on > the NV cpucap and avoid the sysreg read on non-nesting hardware? Yup, good call. I'll add that. Thanks, M.
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 839c76529bb2..3f1c3c91e5c2 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -816,8 +816,6 @@ struct kvm_vcpu_arch { #define DEBUG_STATE_SAVE_SPE __vcpu_single_flag(iflags, BIT(5)) /* Save TRBE context if active */ #define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6)) -/* vcpu running in HYP context */ -#define VCPU_HYP_CONTEXT __vcpu_single_flag(iflags, BIT(7)) /* SVE enabled for host EL0 */ #define HOST_SVE_ENABLED __vcpu_single_flag(sflags, BIT(0)) diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 1581df6aec87..58415783fd53 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -197,7 +197,7 @@ static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) * If we were in HYP context on entry, adjust the PSTATE view * so that the usual helpers work correctly. */ - if (unlikely(vcpu_get_flag(vcpu, VCPU_HYP_CONTEXT))) { + if (unlikely(read_sysreg(hcr_el2) & HCR_NV)) { u64 mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT); switch (mode) { @@ -240,11 +240,6 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) sysreg_restore_guest_state_vhe(guest_ctxt); __debug_switch_to_guest(vcpu); - if (is_hyp_ctxt(vcpu)) - vcpu_set_flag(vcpu, VCPU_HYP_CONTEXT); - else - vcpu_clear_flag(vcpu, VCPU_HYP_CONTEXT); - do { /* Jump in the fire! */ exit_code = __guest_enter(vcpu);