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From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: kvm@vger.kernel.org, kvmarm@lists.linux.dev
Cc: maz@kernel.org, will@kernel.org, catalin.marinas@arm.com,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, steven.price@arm.com,
	aneesh.kumar@kernel.org, oupton@kernel.org, gshan@redhat.com,
	joey.gouly@arm.com, tabba@google.com, yuzenghui@huawei.com,
	linux-coco@lists.linux.dev, gankulkarni@os.amperecomputing.com,
	sdonthineni@nvidia.com, alpergun@google.com,
	fj0570is@fujitsu.com, WeiLin.Chang@arm.com,
	lpieralisi@kernel.org, enju.kohei@fujitsu.com,
	sudeep.holla@arm.com, jonathan.cameron@oss.qualcomm.com,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH v20 06/22] KVM: arm64: Don't call vcpu_set_pauth_traps for pKVM host
Date: Thu, 24 Sep 2026 17:04:48 +0100	[thread overview]
Message-ID: <20260924160504.853911-7-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20260924160504.853911-1-suzuki.poulose@arm.com>

vcpu_set_pauth_traps() bails out and does nothing for pKVM hosts.
Clean this up by moving the is_protected_kvm_enabled() check to the
caller, in preparation for adding VM specific vcpu load/put callbacks.

While at it, do an early return if the vcpu doesn't have ptrauth.

No functional changes

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Changes since v19:
 - New patch, since addition of this to the Refactoring patch makes it a bit
   more bigger and harder to follow
---
 arch/arm64/kvm/arm.c | 52 +++++++++++++++++++++++---------------------
 1 file changed, 27 insertions(+), 25 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 90547fbbc8ad7..849f5fcc26c15 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -631,33 +631,34 @@ void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
 
 static void vcpu_set_pauth_traps(struct kvm_vcpu *vcpu)
 {
-	if (vcpu_has_ptrauth(vcpu) && !is_protected_kvm_enabled()) {
-		/*
-		 * Either we're running an L2 guest, and the API/APK bits come
-		 * from L1's HCR_EL2, or API/APK are both set.
-		 */
-		if (unlikely(is_nested_ctxt(vcpu))) {
-			u64 val;
+	if (!vcpu_has_ptrauth(vcpu))
+		return;
 
-			val = __vcpu_sys_reg(vcpu, HCR_EL2);
-			val &= (HCR_API | HCR_APK);
-			vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK);
-			vcpu->arch.hcr_el2 |= val;
-		} else {
-			vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK);
-		}
+	/*
+	 * Either we're running an L2 guest, and the API/APK bits come
+	 * from L1's HCR_EL2, or API/APK are both set.
+	 */
+	if (unlikely(is_nested_ctxt(vcpu))) {
+		u64 val;
 
-		/*
-		 * Save the host keys if there is any chance for the guest
-		 * to use pauth, as the entry code will reload the guest
-		 * keys in that case.
-		 */
-		if (vcpu->arch.hcr_el2 & (HCR_API | HCR_APK)) {
-			struct kvm_cpu_context *ctxt;
+		val = __vcpu_sys_reg(vcpu, HCR_EL2);
+		val &= (HCR_API | HCR_APK);
+		vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK);
+		vcpu->arch.hcr_el2 |= val;
+	} else {
+		vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK);
+	}
 
-			ctxt = this_cpu_ptr_hyp_sym(kvm_hyp_ctxt);
-			ptrauth_save_keys(ctxt);
-		}
+	/*
+	 * Save the host keys if there is any chance for the guest
+	 * to use pauth, as the entry code will reload the guest
+	 * keys in that case.
+	 */
+	if (vcpu->arch.hcr_el2 & (HCR_API | HCR_APK)) {
+		struct kvm_cpu_context *ctxt;
+
+		ctxt = this_cpu_ptr_hyp_sym(kvm_hyp_ctxt);
+		ptrauth_save_keys(ctxt);
 	}
 }
 
@@ -749,7 +750,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	else
 		vcpu->arch.hcr_el2 |= HCR_TWI;
 
-	vcpu_set_pauth_traps(vcpu);
+	if (!is_protected_kvm_enabled())
+		vcpu_set_pauth_traps(vcpu);
 
 	if (is_protected_kvm_enabled()) {
 		kvm_call_hyp_nvhe(__pkvm_vcpu_load,
-- 
2.43.0


  parent reply	other threads:[~2026-09-24 16:05 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-24 16:04 [PATCH v20 00/22] KVM: arm64: CCA: Add basic plumbing for Realms Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 01/22] KVM: arm64: protected VM: Handle user writes to CNTVCT_EL0/CNTPCT_EL0 Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 02/22] KVM: arm64: Disable Steal time accounting for protected guests Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 03/22] KVM: arm64: Include kvm_emulate.h in kvm/arm_psci.h Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 04/22] KVM: arm64: Avoid including linux/kvm_host.h in kvm_pgtable.h Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 05/22] KVM: arm64: Track the type of VM in kvm_arch Suzuki K Poulose
2026-09-24 16:04 ` Suzuki K Poulose [this message]
2026-09-24 16:04 ` [PATCH v20 07/22] KVM: arm64: Refactor the vcpu_load to allow for VM specific callbacks Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 08/22] KVM: arm64: Add vcpu load/put call backs for flavors Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 09/22] KVM: arm64: Reuse kvm_stage2_unmap_range in kvm_unmap_gfn_range Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 10/22] KVM: arm64: Add VM specific callback for S2 MMU operations Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 11/22] KVM: arm64: Use a local kvm pointer in kvm_handle_guest_abort() Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 12/22] KVM: arm64: Abstract out memory abort handling Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 13/22] KVM: arm64: Mandate VGIC v3 for pKVM VMs and Realms Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 14/22] KVM: arm64: CCA: Add a new mode for supporting Realm guests Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 15/22] KVM: arm64: CCA: Add VCPU load/put for Realms Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 16/22] KVM: arm64: CCA: Add bare minimal S2 operations for Realm Suzuki K Poulose
2026-09-24 16:04 ` [PATCH v20 17/22] KVM: arm64: CCA: Introduce Realms Suzuki K Poulose
2026-09-24 16:05 ` [PATCH v20 18/22] KVM: arm64: CCA: Don't expose unsupported capabilities for realm guests Suzuki K Poulose
2026-09-24 16:05 ` [PATCH v20 19/22] KVM: arm64: CCA: WARN on injected undef exceptions Suzuki K Poulose
2026-09-24 16:05 ` [PATCH v20 20/22] KVM: arm64: CCA: Support timers in realm RECs Suzuki K Poulose
2026-09-24 16:05 ` [PATCH v20 21/22] KVM: arm64: CCA: Expose SVE VL register before VCPU finalization Suzuki K Poulose
2026-09-24 16:05 ` [PATCH v20 22/22] KVM: arm64: CCA: Control user register access for Realms Suzuki K Poulose
2026-10-01 15:53   ` Catalin Marinas
2026-10-01 16:37     ` Suzuki K Poulose

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