On Mon, May 12, 2025 at 11:35 PM Maxim Levitsky <mlevitsk@redhat.com> wrote:
>
> Use kvm_trylock_all_vcpus instead of a custom implementation when locking
> all vCPUs of a VM.
>
> Compile tested only.
>
> Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
For KVM RISC-V:
Tested-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Regards,
Anup
> ---
> arch/riscv/kvm/aia_device.c | 34 ++--------------------------------
> 1 file changed, 2 insertions(+), 32 deletions(-)
>
> diff --git a/arch/riscv/kvm/aia_device.c b/arch/riscv/kvm/aia_device.c
> index 39cd26af5a69..6315821f0d69 100644
> --- a/arch/riscv/kvm/aia_device.c
> +++ b/arch/riscv/kvm/aia_device.c
> @@ -12,36 +12,6 @@
> #include <linux/kvm_host.h>
> #include <linux/uaccess.h>
>
> -static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
> -{
> - struct kvm_vcpu *tmp_vcpu;
> -
> - for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
> - tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
> - mutex_unlock(&tmp_vcpu->mutex);
> - }
> -}
> -
> -static void unlock_all_vcpus(struct kvm *kvm)
> -{
> - unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
> -}
> -
> -static bool lock_all_vcpus(struct kvm *kvm)
> -{
> - struct kvm_vcpu *tmp_vcpu;
> - unsigned long c;
> -
> - kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
> - if (!mutex_trylock(&tmp_vcpu->mutex)) {
> - unlock_vcpus(kvm, c - 1);
> - return false;
> - }
> - }
> -
> - return true;
> -}
> -
> static int aia_create(struct kvm_device *dev, u32 type)
> {
> int ret;
> @@ -53,7 +23,7 @@ static int aia_create(struct kvm_device *dev, u32 type)
> return -EEXIST;
>
> ret = -EBUSY;
> - if (!lock_all_vcpus(kvm))
> + if (kvm_trylock_all_vcpus(kvm))
> return ret;
>
> kvm_for_each_vcpu(i, vcpu, kvm) {
> @@ -65,7 +35,7 @@ static int aia_create(struct kvm_device *dev, u32 type)
> kvm->arch.aia.in_kernel = true;
>
> out_unlock:
> - unlock_all_vcpus(kvm);
> + kvm_unlock_all_vcpus(kvm);
> return ret;
> }
>
> --
> 2.46.0
>