Re: [PATCH V13 10/10] arm/arm64: KVM: add guest SEA support
From: Baicar, Tyler
Date: Tue Mar 28 2017 - 12:36:08 EST
Hello Marc,
On 3/24/2017 8:03 AM, Marc Zyngier wrote:
On 21/03/17 22:47, Tyler Baicar wrote:
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 | 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;
+}
+
Shouldn't this be in the #ifndef __ASSEMBLY__ block? The assembler is
definitely going to barf on that...
I will move this in the next patch set.
#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);
Same remark here.
Same here.
+
#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 */
Otherwise, the KVM changes look good to me. Assuming you fix the two
nits above:
Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Thanks!
Tyler
--
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