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From: Fuad Tabba <tabba@google.com>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org
Cc: maz@kernel.org, oliver.upton@linux.dev, james.clark@linaro.org,
	 will@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com,
	 yuzenghui@huawei.com, catalin.marinas@arm.com,
	broonie@kernel.org
Subject: [PATCH v1 10/12] KVM: arm64: Calculate cptr_el2 traps on activating traps
Date: Wed, 20 Nov 2024 10:52:52 +0000	[thread overview]
Message-ID: <20241120105254.2842020-11-tabba@google.com> (raw)
In-Reply-To: <20241120105254.2842020-1-tabba@google.com>

Similar to VHE, calculate the value of cptr_el2 from scratch on
activate traps. This removes the need to store cptr_el2 in every
vcpu structure. Moreover, some traps, such as whether the guest
owns the fp registers, need to be set on every vcpu run.

Signed-off-by: Fuad Tabba <tabba@google.com>
---
 arch/arm64/include/asm/kvm_host.h |  1 -
 arch/arm64/kvm/arm.c              |  1 -
 arch/arm64/kvm/hyp/nvhe/pkvm.c    | 42 -------------------------------
 arch/arm64/kvm/hyp/nvhe/switch.c  | 30 +++++++++++++++++-----
 4 files changed, 24 insertions(+), 50 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index f333b189fb43..99660d040dda 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -708,7 +708,6 @@ struct kvm_vcpu_arch {
 	u64 hcr_el2;
 	u64 hcrx_el2;
 	u64 mdcr_el2;
-	u64 cptr_el2;
 
 	/* Exception Information */
 	struct kvm_vcpu_fault_info fault;
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index b295218cdc24..8a3d02cf0a7a 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1546,7 +1546,6 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
 	}
 
 	vcpu_reset_hcr(vcpu);
-	vcpu->arch.cptr_el2 = kvm_get_reset_cptr_el2(vcpu);
 
 	/*
 	 * Handle the "start in power-off" case.
diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
index cede527a59d4..c8ab3e59f4b1 100644
--- a/arch/arm64/kvm/hyp/nvhe/pkvm.c
+++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
@@ -83,44 +83,6 @@ static void pvm_init_traps_hcr(struct kvm_vcpu *vcpu)
 	vcpu->arch.hcr_el2 = val;
 }
 
-static void pvm_init_traps_cptr(struct kvm_vcpu *vcpu)
-{
-	struct kvm *kvm = vcpu->kvm;
-	u64 val = vcpu->arch.cptr_el2;
-
-	if (!has_hvhe()) {
-		val |= CPTR_NVHE_EL2_RES1;
-		val &= ~(CPTR_NVHE_EL2_RES0);
-	}
-
-	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, AMU, IMP))
-		val |= CPTR_EL2_TAM;
-
-	/* SVE can be disabled by userspace even if supported. */
-	if (!vcpu_has_sve(vcpu)) {
-		if (has_hvhe())
-			val &= ~(CPACR_ELx_ZEN);
-		else
-			val |= CPTR_EL2_TZ;
-	}
-
-	/* No SME support in KVM. */
-	BUG_ON(kvm_has_feat(kvm, ID_AA64PFR1_EL1, SME, IMP));
-	if (has_hvhe())
-		val &= ~(CPACR_ELx_SMEN);
-	else
-		val |= CPTR_EL2_TSM;
-
-	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, TraceVer, IMP)) {
-		if (has_hvhe())
-			val |= CPACR_EL1_TTA;
-		else
-			val |= CPTR_EL2_TTA;
-	}
-
-	vcpu->arch.cptr_el2 = val;
-}
-
 static void pvm_init_traps_mdcr(struct kvm_vcpu *vcpu)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -191,7 +153,6 @@ 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);
@@ -204,7 +165,6 @@ static int pkvm_vcpu_init_traps(struct pkvm_hyp_vcpu *hyp_vcpu)
 		return ret;
 
 	pvm_init_traps_hcr(vcpu);
-	pvm_init_traps_cptr(vcpu);
 	pvm_init_traps_mdcr(vcpu);
 
 	return 0;
@@ -644,8 +604,6 @@ int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu,
 		return ret;
 	}
 
-	hyp_vcpu->vcpu.arch.cptr_el2 = kvm_get_reset_cptr_el2(&hyp_vcpu->vcpu);
-
 	return 0;
 }
 
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 7786a83d0fa8..e95f1df86748 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -35,14 +35,10 @@ DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);
 
 extern void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
 
-static void __activate_traps(struct kvm_vcpu *vcpu)
+static void __activate_cptr_traps(struct kvm_vcpu *vcpu)
 {
-	u64 val;
-
-	___activate_traps(vcpu, vcpu->arch.hcr_el2);
-	__activate_traps_common(vcpu);
+	u64 val = kvm_get_reset_cptr_el2(vcpu);
 
-	val = vcpu->arch.cptr_el2;
 	val |= CPTR_EL2_TAM;	/* Same bit irrespective of E2H */
 	val |= has_hvhe() ? CPACR_EL1_TTA : CPTR_EL2_TTA;
 	if (cpus_have_final_cap(ARM64_SME)) {
@@ -61,7 +57,29 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
 		__activate_traps_fpsimd32(vcpu);
 	}
 
+	if (vcpu_is_protected(vcpu)) {
+		struct kvm *kvm = vcpu->kvm;
+
+		if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, AMU, IMP))
+			val |= CPTR_EL2_TAM;
+
+		if (!vcpu_has_sve(vcpu)) {
+			if (has_hvhe())
+				val &= ~CPACR_ELx_ZEN;
+			else
+				val |= CPTR_EL2_TZ;
+		}
+	}
+
 	kvm_write_cptr_el2(val);
+}
+
+static void __activate_traps(struct kvm_vcpu *vcpu)
+{
+	___activate_traps(vcpu, vcpu->arch.hcr_el2);
+	__activate_traps_common(vcpu);
+	__activate_cptr_traps(vcpu);
+
 	write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el2);
 
 	if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
-- 
2.47.0.338.g60cca15819-goog


  parent reply	other threads:[~2024-11-20 10:53 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-20 10:52 [PATCH v1 00/12] KVM: arm64: Rework guest VM fixed feature handling and trapping in pKVM Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 01/12] KVM: arm64: Consolidate allowed and restricted VM feature checks Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 02/12] KVM: arm64: Group setting traps for protected VMs by control register Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 03/12] KVM: arm64: Move checking protected vcpu features to a separate function Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 04/12] KVM: arm64: Use KVM extension checks for allowed protected VM capabilities Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 05/12] KVM: arm64: Initialize feature id registers for protected VMs Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 06/12] KVM: arm64: Set protected VM traps based on its view of feature registers Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 07/12] KVM: arm64: Rework specifying restricted features for protected VMs Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 08/12] KVM: arm64: Remove fixed_config.h header Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 09/12] KVM: arm64: Remove redundant setting of HCR_EL2 trap bit Fuad Tabba
2024-11-20 10:52 ` Fuad Tabba [this message]
2024-11-21  8:32   ` [PATCH v1 10/12] KVM: arm64: Calculate cptr_el2 traps on activating traps Quentin Perret
2024-11-21  9:41     ` Fuad Tabba
2024-11-21 10:10       ` Quentin Perret
2024-11-21 13:30         ` Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 11/12] KVM: arm64: Update vcpu state with live value of VBAR_EL1 on injecting an exception Fuad Tabba
2024-11-20 10:52 ` [PATCH v1 12/12] fixup! KVM: arm64: Initialize feature id registers for protected VMs Fuad Tabba
2024-11-20 11:01   ` Fuad Tabba

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