[PATCH v4 11/66] KVM: arm64: nv: Handle trapped ERET from virtual EL2
From: Marc Zyngier <maz@kernel.org>
Date: 2021-05-10 17:32:43
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Christoffer Dall <redacted> When a guest hypervisor running virtual EL2 in EL1 executes an ERET instruction, we will have set HCR_EL2.NV which traps ERET to EL2, so that we can emulate the exception return in software. Signed-off-by: Christoffer Dall <redacted> Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/include/asm/esr.h | 5 +++++ arch/arm64/include/asm/kvm_arm.h | 2 +- arch/arm64/kvm/handle_exit.c | 10 ++++++++++ 3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 29f97eb3dad4..9e6bc2757a05 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h@@ -253,6 +253,11 @@ (((e) & ESR_ELx_SYS64_ISS_OP2_MASK) >> \ ESR_ELx_SYS64_ISS_OP2_SHIFT)) +/* ISS field definitions for ERET/ERETAA/ERETAB trapping */ + +#define ESR_ELx_ERET_ISS_ERET_ERETAx 0x2 +#define ESR_ELx_ERET_ISS_ERETA_ERATAB 0x1 + /* * ISS field definitions for floating-point exception traps * (FP_EXC_32/FP_EXC_64).
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index e27da4165d43..4fd52af7f538 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h@@ -329,7 +329,7 @@ ECN(SP_ALIGN), ECN(FP_EXC32), ECN(FP_EXC64), ECN(SERROR), \ ECN(BREAKPT_LOW), ECN(BREAKPT_CUR), ECN(SOFTSTP_LOW), \ ECN(SOFTSTP_CUR), ECN(WATCHPT_LOW), ECN(WATCHPT_CUR), \ - ECN(BKPT32), ECN(VECTOR32), ECN(BRK64) + ECN(BKPT32), ECN(VECTOR32), ECN(BRK64), ECN(ERET) #define CPACR_EL1_FPEN (3 << 20) #define CPACR_EL1_TTA (1 << 28)
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 6add422d63b8..fca0d44afe96 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c@@ -183,6 +183,15 @@ static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu) return 1; } +static int kvm_handle_eret(struct kvm_vcpu *vcpu) +{ + if (kvm_vcpu_get_esr(vcpu) & ESR_ELx_ERET_ISS_ERET_ERETAx) + return kvm_handle_ptrauth(vcpu); + + kvm_emulate_nested_eret(vcpu); + return 1; +} + static exit_handle_fn arm_exit_handlers[] = { [0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec, [ESR_ELx_EC_WFx] = kvm_handle_wfx,
@@ -197,6 +206,7 @@ static exit_handle_fn arm_exit_handlers[] = { [ESR_ELx_EC_SMC64] = handle_smc, [ESR_ELx_EC_SYS64] = kvm_handle_sys_reg, [ESR_ELx_EC_SVE] = handle_sve, + [ESR_ELx_EC_ERET] = kvm_handle_eret, [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort, [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort, [ESR_ELx_EC_SOFTSTP_LOW]= kvm_handle_guest_debug,
--
2.29.2
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