[PATCH V13 10/10] arm/arm64: KVM: add guest SEA support

Tyler Baicar tbaicar at codeaurora.org
Tue Mar 21 15:47:05 PDT 2017


Currently external aborts are unsupported by the guest abort
handling. Add handling for SEAs so that the host kernel reports
SEAs which occur in the guest kernel.

Signed-off-by: Tyler Baicar <tbaicar at codeaurora.org>
---
 arch/arm/include/asm/kvm_arm.h       | 10 +++++++++
 arch/arm/include/asm/system_misc.h   |  5 +++++
 arch/arm/kvm/mmu.c                   | 41 ++++++++++++++++++++++++++++++------
 arch/arm64/include/asm/kvm_arm.h     | 10 +++++++++
 arch/arm64/include/asm/system_misc.h |  2 ++
 arch/arm64/mm/fault.c                | 19 +++++++++++++++--
 drivers/acpi/apei/ghes.c             | 13 ++++++------
 include/acpi/ghes.h                  |  2 +-
 8 files changed, 86 insertions(+), 16 deletions(-)

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index a3f0b3d..ebf020b 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -187,6 +187,16 @@
 #define FSC_FAULT	(0x04)
 #define FSC_ACCESS	(0x08)
 #define FSC_PERM	(0x0c)
+#define FSC_SEA		(0x10)
+#define FSC_SEA_TTW0	(0x14)
+#define FSC_SEA_TTW1	(0x15)
+#define FSC_SEA_TTW2	(0x16)
+#define FSC_SEA_TTW3	(0x17)
+#define FSC_SECC	(0x18)
+#define FSC_SECC_TTW0	(0x1c)
+#define FSC_SECC_TTW1	(0x1d)
+#define FSC_SECC_TTW2	(0x1e)
+#define FSC_SECC_TTW3	(0x1f)
 
 /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
 #define HPFAR_MASK	(~0xf)
diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h
index a3d61ad..ea45d94 100644
--- a/arch/arm/include/asm/system_misc.h
+++ b/arch/arm/include/asm/system_misc.h
@@ -24,4 +24,9 @@
 
 #endif /* !__ASSEMBLY__ */
 
+static inline int handle_guest_sea(unsigned long addr, unsigned int esr)
+{
+	return -1;
+}
+
 #endif /* __ASM_ARM_SYSTEM_MISC_H */
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 962616f..105b6ab 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -29,6 +29,7 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_emulate.h>
 #include <asm/virt.h>
+#include <asm/system_misc.h>
 
 #include "trace.h"
 
@@ -1406,6 +1407,24 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
 		kvm_set_pfn_accessed(pfn);
 }
 
+static bool is_abort_synchronous(unsigned long fault_status) {
+	switch (fault_status) {
+	case FSC_SEA:
+	case FSC_SEA_TTW0:
+	case FSC_SEA_TTW1:
+	case FSC_SEA_TTW2:
+	case FSC_SEA_TTW3:
+	case FSC_SECC:
+	case FSC_SECC_TTW0:
+	case FSC_SECC_TTW1:
+	case FSC_SECC_TTW2:
+	case FSC_SECC_TTW3:
+		return true;
+	default:
+		return false;
+	}
+}
+
 /**
  * kvm_handle_guest_abort - handles all 2nd stage aborts
  * @vcpu:	the VCPU pointer
@@ -1426,23 +1445,31 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	unsigned long hva;
 	bool is_iabt, write_fault, writable;
 	gfn_t gfn;
-	int ret, idx;
+	int ret, idx, sea_status = 1;
+
+	/* Check the stage-2 fault is trans. fault or write fault */
+	fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
+
+	fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
+
+	/* The host kernel will handle the synchronous external abort. There
+	 * is no need to pass the error into the guest.
+	 */
+	if (is_abort_synchronous(fault_status))
+		sea_status = handle_guest_sea((unsigned long)fault_ipa,
+				    kvm_vcpu_get_hsr(vcpu));
 
 	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
-	if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) {
+	if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu)) && sea_status) {
 		kvm_inject_vabt(vcpu);
 		return 1;
 	}
 
-	fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
-
 	trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
 			      kvm_vcpu_get_hfar(vcpu), fault_ipa);
 
-	/* Check the stage-2 fault is trans. fault or write fault */
-	fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
 	if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
-	    fault_status != FSC_ACCESS) {
+	    fault_status != FSC_ACCESS && sea_status) {
 		kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
 			kvm_vcpu_trap_get_class(vcpu),
 			(unsigned long)kvm_vcpu_trap_get_fault(vcpu),
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 6e99978..61d694c 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -204,6 +204,16 @@
 #define FSC_FAULT	ESR_ELx_FSC_FAULT
 #define FSC_ACCESS	ESR_ELx_FSC_ACCESS
 #define FSC_PERM	ESR_ELx_FSC_PERM
+#define FSC_SEA		ESR_ELx_FSC_EXTABT
+#define FSC_SEA_TTW0	(0x14)
+#define FSC_SEA_TTW1	(0x15)
+#define FSC_SEA_TTW2	(0x16)
+#define FSC_SEA_TTW3	(0x17)
+#define FSC_SECC	(0x18)
+#define FSC_SECC_TTW0	(0x1c)
+#define FSC_SECC_TTW1	(0x1d)
+#define FSC_SECC_TTW2	(0x1e)
+#define FSC_SECC_TTW3	(0x1f)
 
 /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
 #define HPFAR_MASK	(~UL(0xf))
diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h
index bc81243..5b2cecd 100644
--- a/arch/arm64/include/asm/system_misc.h
+++ b/arch/arm64/include/asm/system_misc.h
@@ -58,4 +58,6 @@ void hook_debug_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
 
 #endif	/* __ASSEMBLY__ */
 
+int handle_guest_sea(unsigned long addr, unsigned int esr);
+
 #endif	/* __ASM_SYSTEM_MISC_H */
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index f7372ce..ee96307 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -497,6 +497,7 @@ static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 {
 	struct siginfo info;
+	int ret = 0;
 
 	pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
 		 fault_name(esr), esr, addr);
@@ -508,7 +509,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 	 */
 	if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
 		nmi_enter();
-		ghes_notify_sea();
+		ret = ghes_notify_sea();
 		nmi_exit();
 	}
 
@@ -521,7 +522,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 		info.si_addr  = (void __user *)addr;
 	arm64_notify_die("", regs, &info, esr);
 
-	return 0;
+	return ret;
 }
 
 static const struct fault_info {
@@ -603,6 +604,20 @@ static const char *fault_name(unsigned int esr)
 }
 
 /*
+ * Handle Synchronous External Aborts that occur in a guest kernel.
+ */
+int handle_guest_sea(unsigned long addr, unsigned int esr)
+{
+	int ret = -ENOENT;
+
+	if(IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
+		ret = ghes_notify_sea();
+	}
+
+	return ret;
+}
+
+/*
  * Dispatch a data abort to the relevant handler.
  */
 asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 230b095..81eabc6 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -810,17 +810,18 @@ static int ghes_notify_sci(struct notifier_block *this,
 #ifdef CONFIG_ACPI_APEI_SEA
 static LIST_HEAD(ghes_sea);
 
-void ghes_notify_sea(void)
+int ghes_notify_sea(void)
 {
 	struct ghes *ghes;
+	int ret = -ENOENT;
 
-	/*
-	 * synchronize_rcu() will wait for nmi_exit(), so no need to
-	 * rcu_read_lock().
-	 */
+	rcu_read_lock();
 	list_for_each_entry_rcu(ghes, &ghes_sea, list) {
-		ghes_proc(ghes);
+		if(!ghes_proc(ghes))
+			ret = 0;
 	}
+	rcu_read_unlock();
+	return ret;
 }
 
 static void ghes_sea_add(struct ghes *ghes)
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 18bc935..2a727dc 100644
--- a/include/acpi/ghes.h
+++ b/include/acpi/ghes.h
@@ -99,6 +99,6 @@ static inline void *acpi_hest_generic_data_payload(struct acpi_hest_generic_data
 		gdata + 1;
 }
 
-void ghes_notify_sea(void);
+int ghes_notify_sea(void);
 
 #endif /* GHES_H */
-- 
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Qualcomm Technologies, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.




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