KVM: arm64: Use kvm_has_feat() to check if FEAT_SSBS is advertised to the guest

Currently KVM use cpus_have_final_cap() to check if FEAT_SSBS is
advertised to the guest. But if FEAT_SSBS is writable and isn't
advertised to the guest, this is wrong.

Update it to use kvm_has_feat() to check if FEAT_SSBS is advertised
to the guest, thus the KVM can do the right thing if FEAT_SSBS isn't
advertised to the guest.

Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Link: https://lore.kernel.org/r/20240723072004.1470688-3-shahuang@redhat.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Shaoqin Huang
2024-07-23 03:20:01 -04:00
committed by Marc Zyngier
parent ffe68b2d19
commit e8d164974c

View File

@@ -317,7 +317,7 @@ int kvm_smccc_call_handler(struct kvm_vcpu *vcpu)
* to the guest, and hide SSBS so that the
* guest stays protected.
*/
if (cpus_have_final_cap(ARM64_SSBS))
if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, SSBS, IMP))
break;
fallthrough;
case SPECTRE_UNAFFECTED:
@@ -428,7 +428,7 @@ int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
* Convert the workaround level into an easy-to-compare number, where higher
* values mean better protection.
*/
static int get_kernel_wa_level(u64 regid)
static int get_kernel_wa_level(struct kvm_vcpu *vcpu, u64 regid)
{
switch (regid) {
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
@@ -449,7 +449,7 @@ static int get_kernel_wa_level(u64 regid)
* don't have any FW mitigation if SSBS is there at
* all times.
*/
if (cpus_have_final_cap(ARM64_SSBS))
if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, SSBS, IMP))
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
fallthrough;
case SPECTRE_UNAFFECTED:
@@ -486,7 +486,7 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
val = get_kernel_wa_level(vcpu, reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
break;
case KVM_REG_ARM_STD_BMAP:
val = READ_ONCE(smccc_feat->std_bmap);
@@ -588,7 +588,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
if (val & ~KVM_REG_FEATURE_LEVEL_MASK)
return -EINVAL;
if (get_kernel_wa_level(reg->id) < val)
if (get_kernel_wa_level(vcpu, reg->id) < val)
return -EINVAL;
return 0;
@@ -624,7 +624,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
* We can deal with NOT_AVAIL on NOT_REQUIRED, but not the
* other way around.
*/
if (get_kernel_wa_level(reg->id) < wa_level)
if (get_kernel_wa_level(vcpu, reg->id) < wa_level)
return -EINVAL;
return 0;