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authorSuzuki K Poulose <suzuki.poulose@arm.com>2021-04-05 17:42:53 +0100
committerMathieu Poirier <mathieu.poirier@linaro.org>2021-04-06 16:05:20 -0600
commitd2602bb4f5a450642b96d467e27e6d5d3ef7fa54 (patch)
tree3b8135ff3455cff344767192995cc11662101e00 /arch/arm64/kvm/debug.c
parentcc427cbb15375f1229e78908064cdff98138b8b1 (diff)
KVM: arm64: Move SPE availability check to VCPU load
At the moment, we check the availability of SPE on the given CPU (i.e, SPE is implemented and is allowed at the host) during every guest entry. This can be optimized a bit by moving the check to vcpu_load time and recording the availability of the feature on the current CPU via a new flag. This will also be useful for adding the TRBE support. Cc: Marc Zyngier <maz@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Alexandru Elisei <Alexandru.Elisei@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210405164307.1720226-7-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Diffstat (limited to 'arch/arm64/kvm/debug.c')
-rw-r--r--arch/arm64/kvm/debug.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index dbc890511631..b6d2c33ad1df 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -231,3 +231,26 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu)
}
}
}
+
+void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu)
+{
+ u64 dfr0;
+
+ /* For VHE, there is nothing to do */
+ if (has_vhe())
+ return;
+
+ dfr0 = read_sysreg(id_aa64dfr0_el1);
+ /*
+ * If SPE is present on this CPU and is available at current EL,
+ * we may need to check if the host state needs to be saved.
+ */
+ if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_PMSVER_SHIFT) &&
+ !(read_sysreg_s(SYS_PMBIDR_EL1) & BIT(SYS_PMBIDR_EL1_P_SHIFT)))
+ vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_SPE;
+}
+
+void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.flags &= ~KVM_ARM64_DEBUG_STATE_SAVE_SPE;
+}