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>, Fuad Tabba <tabba@google.com>, Mostafa Saleh <smostafa@google.com>, Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com> Subject: [PATCH v4 10/15] KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 Date: Fri, 19 Apr 2024 11:29:30 +0100 [thread overview] Message-ID: <20240419102935.1935571-11-maz@kernel.org> (raw) In-Reply-To: <20240419102935.1935571-1-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
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>, Fuad Tabba <tabba@google.com>, Mostafa Saleh <smostafa@google.com>, Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com> Subject: [PATCH v4 10/15] KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 Date: Fri, 19 Apr 2024 11:29:30 +0100 [thread overview] Message-ID: <20240419102935.1935571-11-maz@kernel.org> (raw) In-Reply-To: <20240419102935.1935571-1-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
next prev parent reply other threads:[~2024-04-19 10:30 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-04-19 10:29 [PATCH v4 00/15] KVM/arm64: Add NV support for ERET and PAuth Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 01/15] KVM: arm64: Harden __ctxt_sys_reg() against out-of-range values Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 02/15] KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET* Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 03/15] KVM: arm64: Constraint PAuth support to consistent implementations Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 04/15] KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flag Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 05/15] KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2 Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 06/15] KVM: arm64: nv: Add trap forwarding for ERET and SMC Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 07/15] KVM: arm64: nv: Fast-track 'InHost' exception returns Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 08/15] KVM: arm64: nv: Honor HFGITR_EL2.ERET being set Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 09/15] KVM: arm64: nv: Handle HCR_EL2.{API,APK} independently Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier [this message] 2024-04-19 10:29 ` [PATCH v4 10/15] KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 11/15] KVM: arm64: nv: Add kvm_has_pauth() helper Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 12/15] KVM: arm64: nv: Add emulation for ERETAx instructions Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-23 9:22 ` Jon Hunter 2024-04-23 9:22 ` Jon Hunter 2024-04-23 9:40 ` Zenghui Yu 2024-04-23 9:40 ` Zenghui Yu 2024-04-23 11:42 ` Marc Zyngier 2024-04-23 11:42 ` Marc Zyngier 2024-04-23 12:30 ` Jon Hunter 2024-04-23 12:30 ` Jon Hunter 2024-04-23 12:09 ` Jon Hunter 2024-04-23 12:09 ` Jon Hunter 2024-04-19 10:29 ` [PATCH v4 13/15] KVM: arm64: nv: Handle ERETA[AB] instructions Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 14/15] KVM: arm64: nv: Advertise support for PAuth Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 10:29 ` [PATCH v4 15/15] KVM: arm64: Drop trapping of PAuth instructions/keys Marc Zyngier 2024-04-19 10:29 ` Marc Zyngier 2024-04-19 17:59 ` [PATCH v4 00/15] KVM/arm64: Add NV support for ERET and PAuth Oliver Upton 2024-04-19 17:59 ` Oliver Upton 2024-04-20 11:49 ` Marc Zyngier 2024-04-20 11:49 ` Marc Zyngier 2024-04-20 12:18 ` Marc Zyngier 2024-04-20 12:18 ` Marc Zyngier
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20240419102935.1935571-11-maz@kernel.org \ --to=maz@kernel.org \ --cc=catalin.marinas@arm.com \ --cc=james.morse@arm.com \ --cc=joey.gouly@arm.com \ --cc=kvm@vger.kernel.org \ --cc=kvmarm@lists.linux.dev \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=oliver.upton@linux.dev \ --cc=smostafa@google.com \ --cc=suzuki.poulose@arm.com \ --cc=tabba@google.com \ --cc=will@kernel.org \ --cc=yuzenghui@huawei.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.