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From: Fuad Tabba <fuad.tabba@linux.dev>
To: maz@kernel.org, oupton@kernel.org, kvmarm@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: catalin.marinas@arm.com, will@kernel.org, joey.gouly@arm.com,
	seiden@linux.ibm.com, suzuki.poulose@arm.com,
	yuzenghui@huawei.com, mark.rutland@arm.com,
	vdonnefort@google.com, qperret@google.com,
	Sascha.Bischoff@arm.com, steven.price@arm.com, tabba@google.com
Subject: [PATCH 1/7] KVM: arm64: Reject the GICv5 CPU interface hypercalls under pKVM
Date: Tue, 15 Sep 2026 13:38:40 +0100	[thread overview]
Message-ID: <20260915123846.2317931-2-fuad.tabba@linux.dev> (raw)
In-Reply-To: <20260915123846.2317931-1-fuad.tabba@linux.dev>

__vgic_v5_save_apr() and __vgic_v5_restore_vmcr_apr() remain callable
once pKVM has finalised. pKVM never registers a GICv5 vgic, so neither
has a valid caller in protected mode, and on a GICv3 machine both reach
a register that is UNDEFINED at EL2 and panic the hypervisor.

Move both into the band the dispatcher rejects once pKVM has finalised.

Fixes: af325e87af5da ("KVM: arm64: gic-v5: Add vgic-v5 save/restore hyp interface")
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
---
 arch/arm64/include/asm/kvm_asm.h   | 4 ++--
 arch/arm64/kvm/hyp/nvhe/hyp-main.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index e5b92ac09e69e..ea319c496bb26 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -62,6 +62,8 @@ enum __kvm_host_smccc_func {
 	__KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs,
 	__KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs,
 	__KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config,
+	__KVM_HOST_SMCCC_FUNC___vgic_v5_save_apr,
+	__KVM_HOST_SMCCC_FUNC___vgic_v5_restore_vmcr_apr,
 
 	MARKER(__KVM_HOST_SMCCC_FUNC_MIN_PKVM),
 
@@ -87,8 +89,6 @@ enum __kvm_host_smccc_func {
 	__KVM_HOST_SMCCC_FUNC___tracing_write_event,
 	__KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
 	__KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
-	__KVM_HOST_SMCCC_FUNC___vgic_v5_save_apr,
-	__KVM_HOST_SMCCC_FUNC___vgic_v5_restore_vmcr_apr,
 
 	MARKER(__KVM_HOST_SMCCC_FUNC_PKVM_ONLY),
 
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 9a3b92e626adb..7c939baf9c1ba 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -911,6 +911,8 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__kvm_enable_ssbs),
 	HANDLE_FUNC(__vgic_v3_init_lrs),
 	HANDLE_FUNC(__vgic_v3_get_gic_config),
+	HANDLE_FUNC(__vgic_v5_save_apr),
+	HANDLE_FUNC(__vgic_v5_restore_vmcr_apr),
 	HANDLE_FUNC(__pkvm_prot_finalize),
 
 	HANDLE_FUNC(__kvm_adjust_pc),
@@ -932,8 +934,6 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__tracing_write_event),
 	HANDLE_FUNC(__vgic_v3_save_aprs),
 	HANDLE_FUNC(__vgic_v3_restore_vmcr_aprs),
-	HANDLE_FUNC(__vgic_v5_save_apr),
-	HANDLE_FUNC(__vgic_v5_restore_vmcr_apr),
 
 	HANDLE_FUNC(__pkvm_host_share_hyp),
 	HANDLE_FUNC(__pkvm_host_unshare_hyp),
-- 
2.39.5


  reply	other threads:[~2026-09-15 12:38 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-15 12:38 [PATCH 0/7] KVM: arm64: pKVM host hypercall and GICv5 CPU interface fixes Fuad Tabba
2026-09-15 12:38 ` Fuad Tabba [this message]
2026-09-15 14:02   ` [PATCH 1/7] KVM: arm64: Reject the GICv5 CPU interface hypercalls under pKVM Marc Zyngier
2026-09-15 14:12     ` Fuad Tabba
2026-09-15 12:38 ` [PATCH 2/7] KVM: arm64: Reject the stage-2 flush " Fuad Tabba
2026-09-15 12:38 ` [PATCH 3/7] KVM: arm64: Validate the host-provided vgic model in pKVM Fuad Tabba
2026-09-15 12:38 ` [PATCH 4/7] KVM: arm64: Validate the host vCPU's VM before reading it under pKVM Fuad Tabba
2026-09-15 12:38 ` [PATCH 5/7] KVM: arm64: Pin the host vCPU before adjusting its PC " Fuad Tabba
2026-09-15 12:38 ` [PATCH 6/7] KVM: arm64: vgic: Do not access the GICv5 CPU interface from EL1 Fuad Tabba
2026-09-15 12:38 ` [PATCH 7/7] KVM: arm64: Fix stale VGICv3 comments in the nVHE world switch Fuad Tabba

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