[PATCH v3 2/3] arm64: kvm: inject SError with virtual syndrome

Dongjiu Geng gengdongjiu at huawei.com
Sun Apr 30 01:37:56 EDT 2017


when SError happen, kvm notifies kvmtool to generate GHES table
to record the error, then kvmtools inject the SError with specified
virtual syndrome. when switch to guest, a virtual SError will happen with
this specified syndrome.

Signed-off-by: Dongjiu Geng <gengdongjiu at huawei.com>
---
 arch/arm64/include/asm/esr.h         |  2 ++
 arch/arm64/include/asm/kvm_emulate.h | 10 ++++++++++
 arch/arm64/include/asm/kvm_host.h    |  1 +
 arch/arm64/include/asm/sysreg.h      |  3 +++
 arch/arm64/kvm/handle_exit.c         | 25 +++++++++++++++++++------
 arch/arm64/kvm/hyp/switch.c          | 15 ++++++++++++++-
 include/uapi/linux/kvm.h             |  5 +++++
 7 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 22f9c90..d009c99 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -127,6 +127,8 @@
 #define ESR_ELx_WFx_ISS_WFE	(UL(1) << 0)
 #define ESR_ELx_xVC_IMM_MASK	((1UL << 16) - 1)
 
+#define VSESR_ELx_IDS_ISS_MASK    ((1UL << 25) - 1)
+
 /* ESR value templates for specific events */
 
 /* BRK instruction trap from AArch64 state */
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index f5ea0ba..a3259a9 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -148,6 +148,16 @@ static inline u32 kvm_vcpu_get_hsr(const struct kvm_vcpu *vcpu)
 	return vcpu->arch.fault.esr_el2;
 }
 
+static inline u32 kvm_vcpu_get_vsesr(const struct kvm_vcpu *vcpu)
+{
+		return vcpu->arch.fault.vsesr_el2;
+}
+
+static inline void kvm_vcpu_set_vsesr(struct kvm_vcpu *vcpu, unsigned long val)
+{
+		vcpu->arch.fault.vsesr_el2 = val;
+}
+
 static inline int kvm_vcpu_get_condition(const struct kvm_vcpu *vcpu)
 {
 	u32 esr = kvm_vcpu_get_hsr(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index e7705e7..84ed239 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -86,6 +86,7 @@ struct kvm_vcpu_fault_info {
 	u32 esr_el2;		/* Hyp Syndrom Register */
 	u64 far_el2;		/* Hyp Fault Address Register */
 	u64 hpfar_el2;		/* Hyp IPA Fault Address Register */
+	u32 vsesr_el2;		/* Virtual SError Exception Syndrome Register */
 };
 
 /*
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 32964c7..b6afb7a 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -125,6 +125,9 @@
 #define REG_PSTATE_PAN_IMM		sys_reg(0, 0, 4, 0, 4)
 #define REG_PSTATE_UAO_IMM		sys_reg(0, 0, 4, 0, 3)
 
+#define VSESR_EL2			sys_reg(3, 4, 5, 2, 3)
+
+
 #define SET_PSTATE_PAN(x) __emit_inst(0xd5000000 | REG_PSTATE_PAN_IMM |	\
 				      (!!x)<<8 | 0x1f)
 #define SET_PSTATE_UAO(x) __emit_inst(0xd5000000 | REG_PSTATE_UAO_IMM |	\
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index c89d83a..3d024a9 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -180,7 +180,11 @@ static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
 
 static int kvm_handle_guest_sei(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-	unsigned long fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
+	unsigned long hva, fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
+	struct kvm_memory_slot *memslot;
+	int hsr, ret = 1;
+	bool writable;
+	gfn_t gfn;
 
 	if (handle_guest_sei((unsigned long)fault_ipa,
 				kvm_vcpu_get_hsr(vcpu))) {
@@ -190,9 +194,20 @@ static int kvm_handle_guest_sei(struct kvm_vcpu *vcpu, struct kvm_run *run)
 				(unsigned long)kvm_vcpu_get_hsr(vcpu));
 
 		kvm_inject_vabt(vcpu);
+	} else {
+		hsr = kvm_vcpu_get_hsr(vcpu);
+
+		gfn = fault_ipa >> PAGE_SHIFT;
+		memslot = gfn_to_memslot(vcpu->kvm, gfn);
+		hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
+
+		run->exit_reason = KVM_EXIT_INTR;
+		run->intr.syndrome_info = hsr;
+		run->intr.address = hva;
+		ret = 0;
 	}
 
-	return 0;
+	return ret;
 }
 
 /*
@@ -218,8 +233,7 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 			*vcpu_pc(vcpu) -= adj;
 		}
 
-		kvm_handle_guest_sei(vcpu, run);
-		return 1;
+		return kvm_handle_guest_sei(vcpu, run);
 	}
 
 	exception_index = ARM_EXCEPTION_CODE(exception_index);
@@ -228,8 +242,7 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	case ARM_EXCEPTION_IRQ:
 		return 1;
 	case ARM_EXCEPTION_EL1_SERROR:
-		kvm_handle_guest_sei(vcpu, run);
-		return 1;
+		return kvm_handle_guest_sei(vcpu, run);
 	case ARM_EXCEPTION_TRAP:
 		/*
 		 * See ARM ARM B1.14.1: "Hyp traps on instructions
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index aede165..ded6211 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -86,6 +86,13 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
 		isb();
 	}
 	write_sysreg(val, hcr_el2);
+    /* If virtual System Error or Asynchronous Abort is pending. set
+     * the virtual exception syndrome information
+     */
+	if (cpus_have_cap(ARM64_HAS_RAS_EXTN) &&
+			(vcpu->arch.hcr_el2 & HCR_VSE))
+		write_sysreg_s(vcpu->arch.fault.vsesr_el2, VSESR_EL2);
+
 	/* Trap on AArch32 cp15 c15 accesses (EL1 or EL0) */
 	write_sysreg(1 << 15, hstr_el2);
 	/*
@@ -139,9 +146,15 @@ static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu)
 	 * the crucial bit is "On taking a vSError interrupt,
 	 * HCR_EL2.VSE is cleared to 0."
 	 */
-	if (vcpu->arch.hcr_el2 & HCR_VSE)
+	if (vcpu->arch.hcr_el2 & HCR_VSE) {
 		vcpu->arch.hcr_el2 = read_sysreg(hcr_el2);
 
+		if (cpus_have_cap(ARM64_HAS_RAS_EXTN)) {
+			/* set vsesr_el2[24:0] with esr_el2[24:0] */
+			kvm_vcpu_set_vsesr(vcpu, read_sysreg_el2(esr)
+					& VSESR_ELx_IDS_ISS_MASK);
+		}
+	}
 	__deactivate_traps_arch()();
 	write_sysreg(0, hstr_el2);
 	write_sysreg(0, pmuserenr_el0);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 27fe556..bb02909 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -360,6 +360,11 @@ struct kvm_run {
 		struct {
 			__u8 vector;
 		} eoi;
+		/* KVM_EXIT_INTR */
+		struct {
+			__u32 syndrome_info;
+			__u64 address;
+		} intr;
 		/* KVM_EXIT_HYPERV */
 		struct kvm_hyperv_exit hyperv;
 		/* Fix the size of the union. */
-- 
2.10.1




More information about the linux-arm-kernel mailing list