[PULL 4/8] KVM: arm/arm64: Fix guest external abort matching

Christoffer Dall
2017-09-05T14:52:03Z

From: James Morse <james.morse@arm.com>

The ARM-ARM has two bits in the ESR/HSR relevant to external aborts.
A range of {I,D}FSC values (of which bit 5 is always set) and bit 9 'EA'
which provides:
> an IMPLEMENTATION DEFINED classification of External Aborts.

This bit is in addition to the {I,D}FSC range, and has an implementation
defined meaning. KVM should always ignore this bit when handling external
aborts from a guest.

Remove the ESR_ELx_EA definition and rewrite its helper
kvm_vcpu_dabt_isextabt() to check the {I,D}FSC range. This merges
kvm_vcpu_dabt_isextabt() and the recently added is_abort_sea() helper.

CC: Tyler Baicar <tbaicar@codeaurora.org>
Reported-by: gengdongjiu <gengdj.1984@gmail.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
---
arch/arm/include/asm/kvm_arm.h | 1 -
arch/arm/include/asm/kvm_emulate.h | 24 +++++++++++++++++-----
arch/arm64/include/asm/kvm_emulate.h | 24 +++++++++++++++++-----
virt/kvm/arm/mmu.c | 40 ++++++++++--------------------------
4 files changed, 49 insertions(+), 40 deletions(-)

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index ebf020b..c878145 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -227,7 +227,6 @@

#define HSR_DABT_S1PTW (_AC(1, UL) << 7)
#define HSR_DABT_CM (_AC(1, UL) << 8)
-#define HSR_DABT_EA (_AC(1, UL) << 9)

#define kvm_arm_exception_type \
{0, "RESET" }, \
diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index 9a8a45a..98089ff 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -149,11 +149,6 @@ static inline int kvm_vcpu_dabt_get_rd(struct kvm_vcpu *vcpu)
return (kvm_vcpu_get_hsr(vcpu) & HSR_SRT_MASK) >> HSR_SRT_SHIFT;
}

-static inline bool kvm_vcpu_dabt_isextabt(struct kvm_vcpu *vcpu)
-{
- return kvm_vcpu_get_hsr(vcpu) & HSR_DABT_EA;
-}
-
static inline bool kvm_vcpu_dabt_iss1tw(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_DABT_S1PTW;
@@ -206,6 +201,25 @@ static inline u8 kvm_vcpu_trap_get_fault_type(struct kvm_vcpu *vcpu)
return kvm_vcpu_get_hsr(vcpu) & HSR_FSC_TYPE;
}

+static inline bool kvm_vcpu_dabt_isextabt(struct kvm_vcpu *vcpu)
+{
+ switch (kvm_vcpu_trap_get_fault_type(vcpu)) {
+ 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;
+ }
+}
+
static inline u32 kvm_vcpu_hvc_get_imm(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & HSR_HVC_IMM_MASK;
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index fe39e68..e5df3fc 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -188,11 +188,6 @@ static inline int kvm_vcpu_dabt_get_rd(const struct kvm_vcpu *vcpu)
return (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT;
}

-static inline bool kvm_vcpu_dabt_isextabt(const struct kvm_vcpu *vcpu)
-{
- return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_EA);
-}
-
static inline bool kvm_vcpu_dabt_iss1tw(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_S1PTW);
@@ -240,6 +235,25 @@ static inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
return kvm_vcpu_get_hsr(vcpu) & ESR_ELx_FSC_TYPE;
}

+static inline bool kvm_vcpu_dabt_isextabt(const struct kvm_vcpu *vcpu)
+{
+ switch (kvm_vcpu_trap_get_fault_type(vcpu)) {
+ 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;
+ }
+}
+
static inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
{
u32 esr = kvm_vcpu_get_hsr(vcpu);
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 2ea21da..b36945d 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1454,25 +1454,6 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
kvm_set_pfn_accessed(pfn);
}

-static bool is_abort_sea(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
@@ -1498,20 +1479,21 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
fault_status = kvm_vcpu_trap_get_fault_type(vcpu);

fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
+ is_iabt = kvm_vcpu_trap_is_iabt(vcpu);

- /*
- * The host kernel will handle the synchronous external abort. There
- * is no need to pass the error into the guest.
- */
- if (is_abort_sea(fault_status)) {
+ /* Synchronous External Abort? */
+ if (kvm_vcpu_dabt_isextabt(vcpu)) {
+ /*
+ * For RAS the host kernel may handle this abort.
+ * There is no need to pass the error into the guest.
+ */
if (!handle_guest_sea(fault_ipa, kvm_vcpu_get_hsr(vcpu)))
return 1;
- }

- is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
- if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) {
- kvm_inject_vabt(vcpu);
- return 1;
+ if (unlikely(!is_iabt)) {
+ kvm_inject_vabt(vcpu);
+ return 1;
+ }
}

trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
--
2.9.0