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authorFuad Tabba <tabba@google.com>2024-12-16 13:50:43 +0300
committerMarc Zyngier <maz@kernel.org>2024-12-20 16:45:25 +0300
commit1fea164ccf19750c5bea688afd9122eb84eb3a72 (patch)
treef8f1be1d278c44fe56f385f5ef52857d36876f6c /arch/arm64/kvm
parentf50758260bfff393f2a800469b37c45a7ef50376 (diff)
downloadlinux-1fea164ccf19750c5bea688afd9122eb84eb3a72.tar.xz
KVM: arm64: Move checking protected vcpu features to a separate function
At the moment, checks for supported vcpu features for protected VMs are build-time bugs. In the following patch, they will become runtime checks based on the vcpu's features registers. Therefore, consolidate them into one function that would return an error if it encounters an unsupported feature. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20241216105057.579031-4-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm')
-rw-r--r--arch/arm64/kvm/hyp/nvhe/pkvm.c45
1 files changed, 32 insertions, 13 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
index 3af5fca64f67..6a39f68563ae 100644
--- a/arch/arm64/kvm/hyp/nvhe/pkvm.c
+++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
@@ -178,20 +178,11 @@ static void pvm_init_traps_mdcr(struct kvm_vcpu *vcpu)
}
/*
- * Initialize trap register values in protected mode.
+ * Check that cpu features that are neither trapped nor supported are not
+ * enabled for protected VMs.
*/
-static void pkvm_vcpu_init_traps(struct pkvm_hyp_vcpu *hyp_vcpu)
+static int pkvm_check_pvm_cpu_features(struct kvm_vcpu *vcpu)
{
- struct kvm_vcpu *vcpu = &hyp_vcpu->vcpu;
-
- vcpu->arch.cptr_el2 = kvm_get_reset_cptr_el2(vcpu);
- vcpu->arch.mdcr_el2 = 0;
-
- pkvm_vcpu_reset_hcr(vcpu);
-
- if ((!pkvm_hyp_vcpu_is_protected(hyp_vcpu)))
- return;
-
/*
* PAuth is allowed if supported by the system and the vcpu.
* Properly checking for PAuth requires checking various fields in
@@ -218,9 +209,34 @@ static void pkvm_vcpu_init_traps(struct pkvm_hyp_vcpu *hyp_vcpu)
BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AdvSIMD),
PVM_ID_AA64PFR0_ALLOW));
+ return 0;
+}
+
+/*
+ * Initialize trap register values in protected mode.
+ */
+static int pkvm_vcpu_init_traps(struct pkvm_hyp_vcpu *hyp_vcpu)
+{
+ struct kvm_vcpu *vcpu = &hyp_vcpu->vcpu;
+ int ret;
+
+ vcpu->arch.cptr_el2 = kvm_get_reset_cptr_el2(vcpu);
+ vcpu->arch.mdcr_el2 = 0;
+
+ pkvm_vcpu_reset_hcr(vcpu);
+
+ if ((!pkvm_hyp_vcpu_is_protected(hyp_vcpu)))
+ return 0;
+
+ ret = pkvm_check_pvm_cpu_features(vcpu);
+ if (ret)
+ return ret;
+
pvm_init_traps_hcr(vcpu);
pvm_init_traps_cptr(vcpu);
pvm_init_traps_mdcr(vcpu);
+
+ return 0;
}
/*
@@ -417,9 +433,12 @@ static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu,
hyp_vcpu->vcpu.arch.cflags = READ_ONCE(host_vcpu->arch.cflags);
hyp_vcpu->vcpu.arch.mp_state.mp_state = KVM_MP_STATE_STOPPED;
+ ret = pkvm_vcpu_init_traps(hyp_vcpu);
+ if (ret)
+ goto done;
+
pkvm_vcpu_init_sve(hyp_vcpu, host_vcpu);
pkvm_vcpu_init_ptrauth(hyp_vcpu);
- pkvm_vcpu_init_traps(hyp_vcpu);
done:
if (ret)
unpin_host_vcpu(host_vcpu);