On Wed, Jan 29, 2020 at 08:24:40PM +0000, Beata Michalska wrote:
> KVM_SET_VCPU_EVENTS might actually lead to vcpu registers being modified.
> As such this should be the last step of sync to avoid potential overwriting
> of whatever changes KVM might have done.
>
> Signed-off-by: Beata Michalska <beata.michalska@xxxxxxxxxx>
> ---
> target/arm/kvm32.c | 20 ++++++++++----------
> target/arm/kvm64.c | 20 ++++++++++----------
> 2 files changed, 20 insertions(+), 20 deletions(-)
>
> diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
> index 32bf8d6..cf2b47f 100644
> --- a/target/arm/kvm32.c
> +++ b/target/arm/kvm32.c
> @@ -386,17 +386,17 @@ int kvm_arch_put_registers(CPUState *cs, int level)
> return ret;
> }
>
> - ret = kvm_put_vcpu_events(cpu);
> - if (ret) {
> - return ret;
> - }
> -
> write_cpustate_to_list(cpu, true);
>
> if (!write_list_to_kvmstate(cpu, level)) {
> return EINVAL;
> }
>
> + ret = kvm_put_vcpu_events(cpu);
> + if (ret) {
> + return ret;
> + }
> +
I think we should put a comment above this that says basically the same
thing as the commit message in order to explain why kvm_put_vcpu_events()
*must* be after write_list_to_kvmstate().
> kvm_arm_sync_mpstate_to_kvm(cpu);
>
> return ret;
> @@ -462,11 +462,6 @@ int kvm_arch_get_registers(CPUState *cs)
> }
> vfp_set_fpscr(env, fpscr);
>
> - ret = kvm_get_vcpu_events(cpu);
> - if (ret) {
> - return ret;
> - }
> -
> if (!write_kvmstate_to_list(cpu)) {
> return EINVAL;
> }
> @@ -475,6 +470,11 @@ int kvm_arch_get_registers(CPUState *cs)
> */
> write_list_to_cpustate(cpu);
>
> + ret = kvm_get_vcpu_events(cpu);
> + if (ret) {
> + return ret;
> + }
> +
Why are we moving kvm_get_vcpu_events()?
> kvm_arm_sync_mpstate_to_qemu(cpu);
>
> return 0;
> diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
> index 6344113..d06fd32 100644
> --- a/target/arm/kvm64.c
> +++ b/target/arm/kvm64.c
> @@ -1043,17 +1043,17 @@ int kvm_arch_put_registers(CPUState *cs, int level)
> return ret;
> }
>
> - ret = kvm_put_vcpu_events(cpu);
> - if (ret) {
> - return ret;
> - }
> -
> write_cpustate_to_list(cpu, true);
>
> if (!write_list_to_kvmstate(cpu, level)) {
> return -EINVAL;
> }
>
> + ret = kvm_put_vcpu_events(cpu);
> + if (ret) {
> + return ret;
> + }
> +
> kvm_arm_sync_mpstate_to_kvm(cpu);
>
> return ret;
> @@ -1251,11 +1251,6 @@ int kvm_arch_get_registers(CPUState *cs)
> }
> vfp_set_fpcr(env, fpr);
>
> - ret = kvm_get_vcpu_events(cpu);
> - if (ret) {
> - return ret;
> - }
> -
> if (!write_kvmstate_to_list(cpu)) {
> return -EINVAL;
> }
> @@ -1264,6 +1259,11 @@ int kvm_arch_get_registers(CPUState *cs)
> */
> write_list_to_cpustate(cpu);
>
> + ret = kvm_get_vcpu_events(cpu);
> + if (ret) {
> + return ret;
> + }
> +
> kvm_arm_sync_mpstate_to_qemu(cpu);
>
> /* TODO: other registers */
> --
> 2.7.4
>
>
Same comments for kvm64.c as for kvm32.c
Thanks,
drew
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