On vcpu reset, we expect all the registers to be brought back
to their initial state, which happens to be a bunch of zeroes.
However, some recent commit broke this, and is now leaving a bunch
of registers (such as the FP state) with whatever was left by the
guest. My bad.
Zero the reset of the state (32bit SPSRs and FPSIMD state).
Cc: stable@xxxxxxxxxxxxxxx
Fixes: e47c2055c68e ("KVM: arm64: Make struct kvm_regs userspace-only")
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
Notes:
v2: Only reset the FPSIMD state and the AArch32 SPSRs to avoid
corrupting CNTVOFF in creative ways.
arch/arm64/kvm/reset.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index bd354cd45d28..4b5acd84b8c8 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -242,6 +242,11 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
/* Reset core registers */
memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu)));
+ memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
+ vcpu->arch.ctxt.spsr_abt = 0;
+ vcpu->arch.ctxt.spsr_und = 0;
+ vcpu->arch.ctxt.spsr_irq = 0;
+ vcpu->arch.ctxt.spsr_fiq = 0;
vcpu_gp_regs(vcpu)->pstate = pstate;
/* Reset system registers */
--
2.30.2
