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From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: Alexandru Elisei <alexandru.elisei@arm.com>,
	Andre Przywara <andre.przywara@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Christoffer Dall <christoffer.dall@arm.com>,
	Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>,
	Russell King <rmk+kernel@armlinux.org.uk>,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH 11/18] KVM: arm64: nv: Handle trapped ERET from virtual EL2
Date: Thu,  9 Feb 2023 17:58:13 +0000	[thread overview]
Message-ID: <20230209175820.1939006-12-maz@kernel.org> (raw)
In-Reply-To: <20230209175820.1939006-1-maz@kernel.org>

From: Christoffer Dall <christoffer.dall@arm.com>

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@armlinux.org.uk>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 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


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  parent reply	other threads:[~2023-02-09 18:11 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-09 17:58 [PATCH 00/18] KVM: arm64: Prefix patches for NV support Marc Zyngier
2023-02-09 17:58 ` [PATCH 01/18] arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Marc Zyngier
2023-02-09 17:58 ` [PATCH 02/18] KVM: arm64: Use the S2 MMU context to iterate over S2 table Marc Zyngier
2023-02-11  1:00   ` Andre Przywara
2023-02-09 17:58 ` [PATCH 03/18] KVM: arm64: nv: Introduce nested virtualization VCPU feature Marc Zyngier
2023-02-09 17:58 ` [PATCH 04/18] KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set Marc Zyngier
2023-02-09 17:58 ` [PATCH 05/18] KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x Marc Zyngier
2023-02-09 17:58 ` [PATCH 06/18] KVM: arm64: nv: Add EL2 system registers to vcpu context Marc Zyngier
2023-02-09 17:58 ` [PATCH 07/18] KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state Marc Zyngier
2023-02-09 17:58 ` [PATCH 08/18] KVM: arm64: nv: Handle HCR_EL2.NV system register traps Marc Zyngier
2023-02-24 17:39   ` Joey Gouly
2023-02-24 18:36     ` Oliver Upton
2023-02-24 19:03       ` Marc Zyngier
2023-02-09 17:58 ` [PATCH 09/18] KVM: arm64: nv: Support virtual EL2 exceptions Marc Zyngier
2023-02-09 17:58 ` [PATCH 10/18] KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 Marc Zyngier
2023-02-09 17:58 ` Marc Zyngier [this message]
2023-02-09 17:58 ` [PATCH 12/18] KVM: arm64: nv: Handle PSCI call via smc from the guest Marc Zyngier
2023-02-11 10:07   ` Oliver Upton
2023-02-11 10:31     ` Marc Zyngier
2023-02-11 18:17       ` Oliver Upton
2023-02-09 17:58 ` [PATCH 13/18] KVM: arm64: nv: Add accessors for SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2 Marc Zyngier
2023-02-09 17:58 ` [PATCH 14/18] KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor Marc Zyngier
2023-02-09 17:58 ` [PATCH 15/18] KVM: arm64: nv: Allow a sysreg to be hidden from userspace only Marc Zyngier
2023-02-09 17:58 ` [PATCH 16/18] KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 Marc Zyngier
2023-02-09 17:58 ` [PATCH 17/18] KVM: arm64: nv: Filter out unsupported features from ID regs Marc Zyngier
2023-02-09 17:58 ` [PATCH 18/18] KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes Marc Zyngier
2023-02-13 22:26 ` [PATCH 00/18] KVM: arm64: Prefix patches for NV support Oliver Upton

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