[PATCH 18/23] KVM: arm: Make inject_abt32() inject an external abort instead

Marc Zyngier
2020-01-30T13:29:31Z

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

KVM's inject_abt64() injects an external-abort into an aarch64 guest.
The KVM_CAP_ARM_INJECT_EXT_DABT is intended to do exactly this, but
for an aarch32 guest inject_abt32() injects an implementation-defined
exception, 'Lockdown fault'.

Change this to external abort. For non-LPAE we now get the documented:
| Unhandled fault: external abort on non-linefetch (0x008) at 0x9c800f00
and for LPAE:
| Unhandled fault: synchronous external abort (0x210) at 0x9c800f00

Fixes: 74a64a981662a ("KVM: arm/arm64: Unify 32bit fault injection")
Reported-by: Beata Michalska <beata.michalska@linaro.org>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200121123356.203000-3-james.morse@arm.com
---
virt/kvm/arm/aarch32.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/arm/aarch32.c b/virt/kvm/arm/aarch32.c
index 2da482ca7067..0a356aa91aa1 100644
--- a/virt/kvm/arm/aarch32.c
+++ b/virt/kvm/arm/aarch32.c
@@ -15,6 +15,10 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>

+#define DFSR_FSC_EXTABT_LPAE 0x10
+#define DFSR_FSC_EXTABT_nLPAE 0x08
+#define DFSR_LPAE BIT(9)
+
/*
* Table taken from ARMv8 ARM DDI0487B-B, table G1-10.
*/
@@ -182,10 +186,10 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt,
/* Give the guest an IMPLEMENTATION DEFINED exception */
is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31);
if (is_lpae) {
- *fsr = 1 << 9 | 0x34;
+ *fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE;
} else {
- /* Surprise! DFSR's FS[4] lives in bit 10 */
- *fsr = BIT(10) | 0x4; /* 0x14 */
+ /* no need to shuffle FS[4] into DFSR[10] as its 0 */
+ *fsr = DFSR_FSC_EXTABT_nLPAE;
}
}

--
2.20.1