arm64/sve: KVM: Treat guest SVE use as undefined instruction execution

When trapping forbidden attempts by a guest to use SVE, we want the
guest to see a trap consistent with SVE not being implemented.

This patch injects an undefined instruction exception into the
guest in response to such an exception.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 7debb74843a053bfdec33cb69326f3f3d0968297..b712479954692f3efd3844e490b412f71c3a96aa 100644 (file)
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -147,6 +147,13 @@ static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu, struct kvm_run *run)
        return 1;
 }
 
+static int handle_sve(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+       /* Until SVE is supported for guests: */
+       kvm_inject_undefined(vcpu);
+       return 1;
+}
+
 static exit_handle_fn arm_exit_handlers[] = {
        [0 ... ESR_ELx_EC_MAX]  = kvm_handle_unknown_ec,
        [ESR_ELx_EC_WFx]        = kvm_handle_wfx,
@@ -160,6 +167,7 @@ static exit_handle_fn arm_exit_handlers[] = {
        [ESR_ELx_EC_HVC64]      = handle_hvc,
        [ESR_ELx_EC_SMC64]      = handle_smc,
        [ESR_ELx_EC_SYS64]      = kvm_handle_sys_reg,
+       [ESR_ELx_EC_SVE]        = handle_sve,
        [ESR_ELx_EC_IABT_LOW]   = kvm_handle_guest_abort,
        [ESR_ELx_EC_DABT_LOW]   = kvm_handle_guest_abort,
        [ESR_ELx_EC_SOFTSTP_LOW]= kvm_handle_guest_debug,