[PATCH V12 10/10] arm/arm64: KVM: add guest SEA support
From: Tyler Baicar
Date: Mon Mar 06 2017 - 15:49:44 EST
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@xxxxxxxxxxxxxx>
---
arch/arm/include/asm/kvm_arm.h | 10 ++++++++++
arch/arm/include/asm/system_misc.h | 5 +++++
arch/arm/kvm/mmu.c | 36 ++++++++++++++++++++++++++++++++++--
arch/arm64/include/asm/kvm_arm.h | 10 ++++++++++
arch/arm64/include/asm/system_misc.h | 2 ++
arch/arm64/mm/fault.c | 18 ++++++++++++++++++
6 files changed, 79 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index e22089f..a1a3dff 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 a5265ed..f3608c9 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"
@@ -1409,6 +1410,24 @@ 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
@@ -1444,8 +1463,21 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
/* 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) {
+
+ /* 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)) {
+ if(handle_guest_sea((unsigned long)fault_ipa,
+ kvm_vcpu_get_hsr(vcpu))) {
+ kvm_err("Failed to handle guest SEA, FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
+ kvm_vcpu_trap_get_class(vcpu),
+ (unsigned long)kvm_vcpu_trap_get_fault(vcpu),
+ (unsigned long)kvm_vcpu_get_hsr(vcpu));
+ return -EFAULT;
+ }
+ } else if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
+ fault_status != FSC_ACCESS) {
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 2a2752b..dcacdbb 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -201,6 +201,16 @@
#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..5b2cecd1 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 b2d57fc..31c5171 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -602,6 +602,24 @@ 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)
+{
+ /*
+ * synchronize_rcu() will wait for nmi_exit(), so no need to
+ * rcu_read_lock().
+ */
+ if(IS_ENABLED(ACPI_APEI_SEA)) {
+ rcu_read_lock();
+ ghes_notify_sea();
+ rcu_read_unlock();
+ }
+
+ return 0;
+}
+
+/*
* Dispatch a data abort to the relevant handler.
*/
asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
--
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