On Mon, Nov 29, 2021 at 08:00:49PM +0000, Marc Zyngier wrote: > From: Christoffer Dall <[email protected]> > > Reset the VCPU with PSTATE.M = EL2h when the nested virtualization > feature is enabled on the VCPU. > > Signed-off-by: Christoffer Dall <[email protected]> > [maz: rework register reset not to use empty data structures] > Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Russell King (Oracle) <[email protected]> However, a couple of comments below. > --- > arch/arm64/kvm/reset.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > index 426bd7fbc3fd..38a7182819fb 100644 > --- a/arch/arm64/kvm/reset.c > +++ b/arch/arm64/kvm/reset.c > @@ -27,6 +27,7 @@ > #include <asm/kvm_asm.h> > #include <asm/kvm_emulate.h> > #include <asm/kvm_mmu.h> > +#include <asm/kvm_nested.h> > #include <asm/virt.h> > > /* Maximum phys_shift supported for any VM on this host */ > @@ -38,6 +39,9 @@ static u32 kvm_ipa_limit; > #define VCPU_RESET_PSTATE_EL1 (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT > | \ > PSR_F_BIT | PSR_D_BIT) > > +#define VCPU_RESET_PSTATE_EL2 (PSR_MODE_EL2h | PSR_A_BIT | PSR_I_BIT > | \ > + PSR_F_BIT | PSR_D_BIT) > + > #define VCPU_RESET_PSTATE_SVC (PSR_AA32_MODE_SVC | PSR_AA32_A_BIT | \ > PSR_AA32_I_BIT | PSR_AA32_F_BIT) > > @@ -176,8 +180,8 @@ static bool vcpu_allowed_register_width(struct kvm_vcpu > *vcpu) > if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1) && is32bit) > return false; > > - /* MTE is incompatible with AArch32 */ > - if (kvm_has_mte(vcpu->kvm) && is32bit) > + /* MTE and NV are incompatible with AArch32 */ > + if ((kvm_has_mte(vcpu->kvm) || nested_virt_in_use(vcpu)) && is32bit) > return false; It seems we have a bunch of: if (something && is32bit) return false; tests here - would it make sense to do: if (is32bit) { if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) return false; /* MTE is incompatible with AArch32 */ if (kvm_has_mte(vcpu->kvm)) return false; /* NV is incompatible with AArch32 */ if (nested_virt_in_use(vcpu)) return false; } in terms of improved readability? > @@ -255,6 +259,8 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) > default: > if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) { > pstate = VCPU_RESET_PSTATE_SVC; > + } else if (nested_virt_in_use(vcpu)) { > + pstate = VCPU_RESET_PSTATE_EL2; > } else { > pstate = VCPU_RESET_PSTATE_EL1; > } Not an issue with your patch, but the switch around this looks useless. The only case is this default case, so it's entirely a no-op. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
