From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Andrew Scull <ascull@google.com>, Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Quentin Perret <qperret@google.com>,
David Brazdil <dbrazdil@google.com>,
kernel-team@android.com
Subject: [PATCH v2 04/11] KVM: arm64: Move PC rollback on SError to HYP
Date: Mon, 2 Nov 2020 16:40:38 +0000 [thread overview]
Message-ID: <20201102164045.264512-5-maz@kernel.org> (raw)
In-Reply-To: <20201102164045.264512-1-maz@kernel.org>
Instead of handling the "PC rollback on SError during HVC" at EL1 (which
requires disclosing PC to a potentially untrusted kernel), let's move
this fixup to ... fixup_guest_exit(), which is where we do all fixups.
Isn't that neat?
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/handle_exit.c | 17 -----------------
arch/arm64/kvm/hyp/include/hyp/switch.h | 15 +++++++++++++++
2 files changed, 15 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index d4e00a864ee6..f79137ee4274 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -241,23 +241,6 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index)
{
struct kvm_run *run = vcpu->run;
- if (ARM_SERROR_PENDING(exception_index)) {
- u8 esr_ec = ESR_ELx_EC(kvm_vcpu_get_esr(vcpu));
-
- /*
- * HVC already have an adjusted PC, which we need to
- * correct in order to return to after having injected
- * the SError.
- *
- * SMC, on the other hand, is *trapped*, meaning its
- * preferred return address is the SMC itself.
- */
- if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64)
- *vcpu_pc(vcpu) -= 4;
-
- return 1;
- }
-
exception_index = ARM_EXCEPTION_CODE(exception_index);
switch (exception_index) {
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 8b2328f62a07..84473574c2e7 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -411,6 +411,21 @@ static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code)
if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ)
vcpu->arch.fault.esr_el2 = read_sysreg_el2(SYS_ESR);
+ if (ARM_SERROR_PENDING(*exit_code)) {
+ u8 esr_ec = kvm_vcpu_trap_get_class(vcpu);
+
+ /*
+ * HVC already have an adjusted PC, which we need to
+ * correct in order to return to after having injected
+ * the SError.
+ *
+ * SMC, on the other hand, is *trapped*, meaning its
+ * preferred return address is the SMC itself.
+ */
+ if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64)
+ write_sysreg_el2(read_sysreg_el2(SYS_ELR) - 4, SYS_ELR);
+ }
+
/*
* We're using the raw exception code in order to only process
* the trap if no SError is pending. We will come back to the
--
2.28.0
next prev parent reply other threads:[~2020-11-02 16:41 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-02 16:40 [PATCH v2 00/11] KVM: arm64: Move PC/ELR/SPSR/PSTATE updatess to EL2 Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 01/11] KVM: arm64: Don't adjust PC on SError during SMC trap Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 02/11] KVM: arm64: Move kvm_vcpu_trap_il_is32bit into kvm_skip_instr32() Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 03/11] KVM: arm64: Make kvm_skip_instr() and co private to HYP Marc Zyngier
2021-05-05 14:23 ` Zenghui Yu
2021-05-05 16:46 ` Marc Zyngier
2021-05-06 6:33 ` Marc Zyngier
2021-05-06 11:43 ` Zenghui Yu
2021-05-06 14:29 ` Marc Zyngier
2021-05-09 13:07 ` Zenghui Yu
2021-05-10 7:59 ` Marc Zyngier
2021-05-06 17:17 ` Marc Zyngier
2020-11-02 16:40 ` Marc Zyngier [this message]
2020-11-02 16:40 ` [PATCH v2 05/11] KVM: arm64: Move VHE direct sysreg accessors into kvm_host.h Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 06/11] KVM: arm64: Add basic hooks for injecting exceptions from EL2 Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 07/11] KVM: arm64: Inject AArch64 exceptions from HYP Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 08/11] KVM: arm64: Inject AArch32 " Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 09/11] KVM: arm64: Remove SPSR manipulation primitives Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 10/11] KVM: arm64: Consolidate exception injection Marc Zyngier
2020-11-02 16:40 ` [PATCH v2 11/11] KVM: arm64: Get rid of the AArch32 register mapping code Marc Zyngier
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