Thread (31 messages) 31 messages, 7 authors, 2017-03-22
STALE3388d

[PATCH V11 10/10] arm/arm64: KVM: add guest SEA support

From: Shiju Jose <hidden>
Date: 2017-03-03 15:34:59
Also in: kvmarm

Hi Tyler,
quoted hunk ↗ jump to hunk
-----Original Message-----
From: Tyler Baicar [mailto:tbaicar at codeaurora.org]
Sent: 21 February 2017 21:22
To: christoffer.dall at linaro.org; marc.zyngier at arm.com;
pbonzini at redhat.com; rkrcmar at redhat.com; linux at armlinux.org.uk;
catalin.marinas at arm.com; will.deacon at arm.com; rjw at rjwysocki.net;
lenb at kernel.org; matt at codeblueprint.co.uk; robert.moore at intel.com;
lv.zheng at intel.com; nkaje at codeaurora.org; zjzhang at codeaurora.org;
mark.rutland at arm.com; james.morse at arm.com; akpm at linux-foundation.org;
eun.taik.lee at samsung.com; sandeepa.s.prabhu at gmail.com;
labbott at redhat.com; shijie.huang at arm.com; rruigrok at codeaurora.org;
paul.gortmaker at windriver.com; tn at semihalf.com; fu.wei at linaro.org;
rostedt at goodmis.org; bristot at redhat.com; linux-arm-
kernel at lists.infradead.org; kvmarm at lists.cs.columbia.edu;
kvm at vger.kernel.org; linux-kernel at vger.kernel.org; linux-
acpi at vger.kernel.org; linux-efi at vger.kernel.org; devel at acpica.org;
Suzuki.Poulose at arm.com; punit.agrawal at arm.com; astone at redhat.com;
harba at codeaurora.org; hanjun.guo at linaro.org; John Garry; Shiju Jose;
joe at perches.com
Cc: Tyler Baicar
Subject: [PATCH V11 10/10] arm/arm64: KVM: add guest SEA support

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 <redacted>
---
 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
b2d57fc..403277b 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)) {
IS_ENABLED(HAVE_ACPI_APEI_SEA) to be changed to IS_ENABLED(ACPI_APEI_SEA) same
as in the patch "acpi: apei: handle SEA notification type for ARMv8"?

Thanks,
Shiju
+		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,
--
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a
Linux Foundation Collaborative Project.
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help