From: Christoffer Dall <christoffer.dall@xxxxxxx> 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. Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Reviewed-by: Alexandru Elisei <alexandru.elisei@xxxxxxx> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxx> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> --- arch/arm64/include/asm/esr.h | 4 ++++ arch/arm64/include/asm/kvm_arm.h | 2 +- arch/arm64/kvm/handle_exit.c | 10 ++++++++++ 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index 206de10524e3..d4dd949b921e 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -272,6 +272,10 @@ (((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 0x2 +#define ESR_ELx_ERET_ISS_ERETA 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 bea827b76c22..e24825dcda6b 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -344,7 +344,7 @@ 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_TTA (1 << 28) #define CPACR_EL1_DEFAULT (CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN |\ diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 2d8c09cf3e49..e75101f2aa6c 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -207,6 +207,15 @@ 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) + 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, @@ -222,6 +231,7 @@ 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, -- 2.34.1