[PATCH] KVM: arm64: Populate fault info for watchpoint

From: Akihiko Odaki
Date: Sun May 28 2023 - 22:49:00 EST


When handling ESR_ELx_EC_WATCHPT_LOW, far_el2 member of struct
kvm_vcpu_fault_info will be copied to far member of struct
kvm_debug_exit_arch and exposed to the userspace. The userspace will
see stale values from older faults if the fault info does not get
populated.

Fixes: 8fb2046180a0 ("KVM: arm64: Move early handlers to per-EC handlers")
Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx>
---
arch/arm64/kvm/hyp/include/hyp/switch.h | 2 +-
arch/arm64/kvm/hyp/nvhe/switch.c | 6 ++++--
arch/arm64/kvm/hyp/vhe/switch.c | 3 ++-
3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 07d37ff88a3f..2eb0a1481ead 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -351,7 +351,7 @@ static bool kvm_hyp_handle_cp15_32(struct kvm_vcpu *vcpu, u64 *exit_code)
return false;
}

-static bool kvm_hyp_handle_iabt_low(struct kvm_vcpu *vcpu, u64 *exit_code)
+static bool kvm_hyp_handle_generic_fault(struct kvm_vcpu *vcpu, u64 *exit_code)
{
if (!__populate_fault_info(vcpu))
return true;
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index c2cb46ca4fb6..1b77866079dc 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -184,8 +184,9 @@ static const exit_handler_fn hyp_exit_handlers[] = {
[ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg,
[ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd,
[ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd,
- [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low,
+ [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_generic_fault,
[ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low,
+ [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_generic_fault,
[ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth,
};

@@ -194,8 +195,9 @@ static const exit_handler_fn pvm_exit_handlers[] = {
[ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64,
[ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted,
[ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd,
- [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low,
+ [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_generic_fault,
[ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low,
+ [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_generic_fault,
[ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth,
};

diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 1a97391fedd2..08ae0ee4697b 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -108,8 +108,9 @@ static const exit_handler_fn hyp_exit_handlers[] = {
[ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg,
[ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd,
[ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd,
- [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low,
+ [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_generic_fault,
[ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low,
+ [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_generic_fault,
[ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth,
};

--
2.40.1