[PATCH V9 10/10] arm/arm64: KVM: add guest SEA support

From: Tyler Baicar <tbaicar@codeaurora.org>
To: christoffer.dall@linaro.org, marc.zyngier@arm.com,
	pbonzini@redhat.com, rkrcmar@redhat.com, linux@armlinux.org.uk,
	catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net,
	lenb@kernel.org, matt@codeblueprint.co.uk,
	robert.moore@intel.com, lv.zheng@intel.com, nkaje@codeaurora.org,
	zjzhang@codeaurora.org, mark.rutland@arm.com,
	james.morse@arm.com, akpm@linux-foundation.org,
	eun.taik.lee@samsung.com, sandeepa.s.prabhu@gmail.com,
	labbott@redhat.com, shijie.huang@arm.com,
	rruigrok@codeaurora.org, paul.gortmaker@windriver.com,
	tn@semihalf.com, fu.wei@linaro.org, rostedt@goodmis.org,
	bristot@redhat.com, linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
	linux-efi@vger.kernel.org, devel@acpica.org,
	Suzuki.Poulose@arm.com, punit.agrawal@arm.com, astone@redhat.com,
	harba@codeaur
Cc: Tyler Baicar <tbaicar@codeaurora.org>
Subject: [PATCH V9 10/10] arm/arm64: KVM: add guest SEA support
Date: Wed, 15 Feb 2017 10:44:52 -0700	[thread overview]
Message-ID: <1487180692-16732-11-git-send-email-tbaicar@codeaurora.org> (raw)
In-Reply-To: <1487180692-16732-1-git-send-email-tbaicar@codeaurora.org>

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@codeaurora.org>
---
 arch/arm/include/asm/kvm_arm.h       |  1 +
 arch/arm/include/asm/system_misc.h   |  5 +++++
 arch/arm/kvm/mmu.c                   | 18 ++++++++++++++++--
 arch/arm64/include/asm/kvm_arm.h     |  1 +
 arch/arm64/include/asm/system_misc.h |  2 ++
 arch/arm64/mm/fault.c                | 18 ++++++++++++++++++
 6 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index e22089f..33a77509 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -187,6 +187,7 @@
 #define FSC_FAULT	(0x04)
 #define FSC_ACCESS	(0x08)
 #define FSC_PERM	(0x0c)
+#define FSC_EXTABT	(0x10)
 
 /* 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..04f1dd50 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"
 
@@ -1444,8 +1445,21 @@ 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 (fault_status == FSC_EXTABT) {
+		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..2b11d59 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -201,6 +201,7 @@
 #define FSC_FAULT	ESR_ELx_FSC_FAULT
 #define FSC_ACCESS	ESR_ELx_FSC_ACCESS
 #define FSC_PERM	ESR_ELx_FSC_PERM
+#define FSC_EXTABT	ESR_ELx_FSC_EXTABT
 
 /* 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 4e35c72..ae8b7c6 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(HAVE_ACPI_APEI_SEA)) {
+		nmi_enter();
+		ghes_notify_sea();
+		nmi_exit();
+	}
+
+	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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