[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-arm] [PATCH v2 12/14] target/arm/kvm: scratch vcpu: Preserve i
From: |
Auger Eric |
Subject: |
Re: [Qemu-arm] [PATCH v2 12/14] target/arm/kvm: scratch vcpu: Preserve input kvm_vcpu_init features |
Date: |
Thu, 27 Jun 2019 09:30:57 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 |
Hi Drew,
On 6/21/19 6:34 PM, Andrew Jones wrote:
> kvm_arm_create_scratch_host_vcpu() takes a struct kvm_vcpu_init
> parameter. Rather than just using it as an output parameter to
> pass back the preferred target, use it also as an input parameter,
> allowing a caller to pass a selected target if they wish and to
> also pass cpu features. If the caller doesn't want to select a
> target they can pass -1 for the target which indicates they want
> to use the preferred target and have it passed back like before.
>
> Signed-off-by: Andrew Jones <address@hidden>
> ---
> target/arm/kvm.c | 20 +++++++++++++++-----
> target/arm/kvm32.c | 6 +++++-
> target/arm/kvm64.c | 6 +++++-
> 3 files changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/target/arm/kvm.c b/target/arm/kvm.c
> index 60645a196d3d..66c0c198604a 100644
> --- a/target/arm/kvm.c
> +++ b/target/arm/kvm.c
> @@ -64,7 +64,7 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t
> *cpus_to_try,
> int *fdarray,
> struct kvm_vcpu_init *init)
> {
> - int ret, kvmfd = -1, vmfd = -1, cpufd = -1;
> + int ret = 0, kvmfd = -1, vmfd = -1, cpufd = -1;
>
> kvmfd = qemu_open("/dev/kvm", O_RDWR);
> if (kvmfd < 0) {
> @@ -84,7 +84,14 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t
> *cpus_to_try,
> goto finish;
> }
>
> - ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, init);
> + if (init->target == -1) {
> + struct kvm_vcpu_init preferred;
> +
> + ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, &preferred);
> + if (!ret) {
> + init->target = preferred.target;
wouldn't it be safe to copy the whole struct. Kernel code says:
/*
* For now, we don't return any features.
* In future, we might use features to return target
* specific features available for the preferred
* target type.
*/
> + }
> + }
> if (ret >= 0) {
> ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init);
> if (ret < 0) {
> @@ -96,10 +103,12 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t
> *cpus_to_try,
> * creating one kind of guest CPU which is its preferred
> * CPU type.
> */
> + struct kvm_vcpu_init try;
> +
> while (*cpus_to_try != QEMU_KVM_ARM_TARGET_NONE) {
> - init->target = *cpus_to_try++;
> - memset(init->features, 0, sizeof(init->features));
> - ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init);
> + try.target = *cpus_to_try++;
> + memcpy(try.features, init->features, sizeof(init->features));
> + ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, &try);
> if (ret >= 0) {
> break;
> }
> @@ -107,6 +116,7 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t
> *cpus_to_try,
> if (ret < 0) {
> goto err;
> }
> + init->target = try.target;
> } else {
> /* Treat a NULL cpus_to_try argument the same as an empty
> * list, which means we will fail the call since this must
> diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
> index 51f78f722b18..d007f6bd34d7 100644
> --- a/target/arm/kvm32.c
> +++ b/target/arm/kvm32.c
> @@ -54,7 +54,11 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures
> *ahcf)
> QEMU_KVM_ARM_TARGET_CORTEX_A15,
> QEMU_KVM_ARM_TARGET_NONE
> };
> - struct kvm_vcpu_init init;
> + /*
> + * target = -1 informs kvm_arm_create_scratch_host_vcpu()
> + * to use the preferred target
> + */
> + struct kvm_vcpu_init init = { .target = -1, };
>
> if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) {
> return false;
> diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
> index 9fc7f078cf68..2821135a4d0e 100644
> --- a/target/arm/kvm64.c
> +++ b/target/arm/kvm64.c
> @@ -502,7 +502,11 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures
> *ahcf)
> KVM_ARM_TARGET_CORTEX_A57,
> QEMU_KVM_ARM_TARGET_NONE
> };
> - struct kvm_vcpu_init init;
> + /*
> + * target = -1 informs kvm_arm_create_scratch_host_vcpu()
> + * to use the preferred target
> + */
> + struct kvm_vcpu_init init = { .target = -1, };
>
> if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) {
> return false;
>
Besides
Reviewed-by: Eric Auger <address@hidden>
Thanks
Eric
- Re: [Qemu-arm] [Qemu-devel] [PATCH v2 07/14] target/arm/cpu64: max cpu: Introduce sve<vl-bits> properties, (continued)
Re: [Qemu-arm] [PATCH v2 07/14] target/arm/cpu64: max cpu: Introduce sve<vl-bits> properties, Richard Henderson, 2019/06/27
[Qemu-arm] [PATCH v2 11/14] target/arm/kvm64: max cpu: Enable SVE when available, Andrew Jones, 2019/06/21
[Qemu-arm] [PATCH v2 12/14] target/arm/kvm: scratch vcpu: Preserve input kvm_vcpu_init features, Andrew Jones, 2019/06/21
[Qemu-arm] [PATCH v2 14/14] target/arm/kvm: host cpu: Add support for sve<vl-bits> properties, Andrew Jones, 2019/06/21
[Qemu-arm] [PATCH v2 13/14] target/arm/cpu64: max cpu: Support sve properties with KVM, Andrew Jones, 2019/06/21