From: Marc Zyngier <maz@kernel.org> To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse <james.morse@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Oliver Upton <oliver.upton@linux.dev>, Zenghui Yu <yuzenghui@huawei.com>, Joey Gouly <joey.gouly@arm.com>, Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com> Subject: [PATCH v2 09/13] KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 Date: Mon, 26 Feb 2024 10:05:57 +0000 [thread overview] Message-ID: <20240226100601.2379693-10-maz@kernel.org> (raw) In-Reply-To: <20240226100601.2379693-1-maz@kernel.org> In order for a L1 hypervisor to correctly handle PAuth instructions, it must observe traps caused by a L1 PAuth instruction when HCR_EL2.API==0. Since we already handle the case for API==1 as a fixup, only the exception injection case needs to be handled. Rework the kvm_handle_ptrauth() callback to reinject the trap in this case. Note that APK==0 is already handled by the exising triage_sysreg_trap() helper. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kvm/handle_exit.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 6a88ec024e2f..1ba2f788b2c3 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -214,12 +214,34 @@ static int handle_sve(struct kvm_vcpu *vcpu) } /* - * Guest usage of a ptrauth instruction (which the guest EL1 did not turn into - * a NOP). If we get here, it is that we didn't fixup ptrauth on exit, and all - * that we can do is give the guest an UNDEF. + * Two possibilities to handle a trapping ptrauth instruction: + * + * - Guest usage of a ptrauth instruction (which the guest EL1 did not + * turn into a NOP). If we get here, it is that we didn't fixup + * ptrauth on exit, and all that we can do is give the guest an + * UNDEF (as the guest isn't supposed to use ptrauth without being + * told it could). + * + * - Running an L2 NV guest while L1 has left HCR_EL2.API==0, and for + * which we reinject the exception into L1. API==1 is handled as a + * fixup so the only way to get here is when API==0. + * + * Anything else is an emulation bug (hence the WARN_ON + UNDEF). */ static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu) { + if (!vcpu_has_ptrauth(vcpu)) { + kvm_inject_undefined(vcpu); + return 1; + } + + if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) { + kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + return 1; + } + + /* Really shouldn't be here! */ + WARN_ON_ONCE(1); kvm_inject_undefined(vcpu); return 1; } -- 2.39.2
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org> To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse <james.morse@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Oliver Upton <oliver.upton@linux.dev>, Zenghui Yu <yuzenghui@huawei.com>, Joey Gouly <joey.gouly@arm.com>, Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com> Subject: [PATCH v2 09/13] KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 Date: Mon, 26 Feb 2024 10:05:57 +0000 [thread overview] Message-ID: <20240226100601.2379693-10-maz@kernel.org> (raw) In-Reply-To: <20240226100601.2379693-1-maz@kernel.org> In order for a L1 hypervisor to correctly handle PAuth instructions, it must observe traps caused by a L1 PAuth instruction when HCR_EL2.API==0. Since we already handle the case for API==1 as a fixup, only the exception injection case needs to be handled. Rework the kvm_handle_ptrauth() callback to reinject the trap in this case. Note that APK==0 is already handled by the exising triage_sysreg_trap() helper. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kvm/handle_exit.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 6a88ec024e2f..1ba2f788b2c3 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -214,12 +214,34 @@ static int handle_sve(struct kvm_vcpu *vcpu) } /* - * Guest usage of a ptrauth instruction (which the guest EL1 did not turn into - * a NOP). If we get here, it is that we didn't fixup ptrauth on exit, and all - * that we can do is give the guest an UNDEF. + * Two possibilities to handle a trapping ptrauth instruction: + * + * - Guest usage of a ptrauth instruction (which the guest EL1 did not + * turn into a NOP). If we get here, it is that we didn't fixup + * ptrauth on exit, and all that we can do is give the guest an + * UNDEF (as the guest isn't supposed to use ptrauth without being + * told it could). + * + * - Running an L2 NV guest while L1 has left HCR_EL2.API==0, and for + * which we reinject the exception into L1. API==1 is handled as a + * fixup so the only way to get here is when API==0. + * + * Anything else is an emulation bug (hence the WARN_ON + UNDEF). */ static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu) { + if (!vcpu_has_ptrauth(vcpu)) { + kvm_inject_undefined(vcpu); + return 1; + } + + if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) { + kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + return 1; + } + + /* Really shouldn't be here! */ + WARN_ON_ONCE(1); kvm_inject_undefined(vcpu); return 1; } -- 2.39.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-02-26 10:07 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-02-26 10:05 [PATCH v2 00/13] KVM/arm64: Add NV support for ERET and PAuth Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 01/13] KVM: arm64: Harden __ctxt_sys_reg() against out-of-range values Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 02/13] KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET* Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 03/13] KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flag Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 04/13] KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2 Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 05/13] KVM: arm64: nv: Add trap forwarding for ERET and SMC Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 06/13] KVM: arm64: nv: Fast-track 'InHost' exception returns Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-02-28 16:08 ` Joey Gouly 2024-02-28 16:08 ` Joey Gouly 2024-02-29 13:44 ` Marc Zyngier 2024-02-29 13:44 ` Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 07/13] KVM: arm64: nv: Honor HFGITR_EL2.ERET being set Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-03-01 18:07 ` Joey Gouly 2024-03-01 18:07 ` Joey Gouly 2024-03-01 19:14 ` Marc Zyngier 2024-03-01 19:14 ` Marc Zyngier 2024-03-01 20:15 ` Joey Gouly 2024-03-01 20:15 ` Joey Gouly 2024-02-26 10:05 ` [PATCH v2 08/13] KVM: arm64: nv: Handle HCR_EL2.{API,APK} independently Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-03-07 15:14 ` Joey Gouly 2024-03-07 15:14 ` Joey Gouly 2024-03-07 15:58 ` Marc Zyngier 2024-03-07 15:58 ` Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier [this message] 2024-02-26 10:05 ` [PATCH v2 09/13] KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 10/13] KVM: arm64: nv: Add kvm_has_pauth() helper Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-02-26 10:05 ` [PATCH v2 11/13] KVM: arm64: nv: Add emulation for ERETAx instructions Marc Zyngier 2024-02-26 10:05 ` Marc Zyngier 2024-03-07 13:39 ` Joey Gouly 2024-03-07 13:39 ` Joey Gouly 2024-03-07 14:24 ` Marc Zyngier 2024-03-07 14:24 ` Marc Zyngier 2024-03-08 17:20 ` Joey Gouly 2024-03-08 17:20 ` Joey Gouly 2024-03-08 17:54 ` Marc Zyngier 2024-03-08 17:54 ` Marc Zyngier 2024-03-12 10:46 ` Joey Gouly 2024-03-12 10:46 ` Joey Gouly 2024-02-26 10:06 ` [PATCH v2 12/13] KVM: arm64: nv: Handle ERETA[AB] instructions Marc Zyngier 2024-02-26 10:06 ` Marc Zyngier 2024-03-12 11:17 ` Joey Gouly 2024-03-12 11:17 ` Joey Gouly 2024-02-26 10:06 ` [PATCH v2 13/13] KVM: arm64: nv: Advertise support for PAuth Marc Zyngier 2024-02-26 10:06 ` Marc Zyngier 2024-03-12 11:21 ` Joey Gouly 2024-03-12 11:21 ` Joey Gouly
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