* Re: [PATCH] KVM: arm64: vgic-v4: Initialize GICv4.1 even in the absence of a virtual ITS
@ 2020-04-30 11:24 ` Zenghui Yu
0 siblings, 0 replies; 9+ messages in thread
From: Zenghui Yu @ 2020-04-30 11:24 UTC (permalink / raw)
To: Marc Zyngier, linux-arm-kernel, kvm, kvmarm
Cc: Eric Auger, James Morse, Julien Thierry, Suzuki K Poulose
Hi Marc,
On 2020/4/25 17:44, Marc Zyngier wrote:
> KVM now expects to be able to use HW-accelerated delivery of vSGIs
> as soon as the guest has enabled thm. Unfortunately, we only
them
> initialize the GICv4 context if we have a virtual ITS exposed to
> the guest.
>
> Fix it by always initializing the GICv4.1 context if it is
> available on the host.
>
> Fixes: 2291ff2f2a56 ("KVM: arm64: GICv4.1: Plumb SGI implementation selection in the distributor")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> virt/kvm/arm/vgic/vgic-init.c | 9 ++++++++-
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 ++-
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index a963b9d766b73..8e6f350c3bcd1 100644
> --- a/virt/kvm/arm/vgic/vgic-init.c
> +++ b/virt/kvm/arm/vgic/vgic-init.c
> @@ -294,8 +294,15 @@ int vgic_init(struct kvm *kvm)
> }
> }
>
> - if (vgic_has_its(kvm)) {
> + if (vgic_has_its(kvm))
> vgic_lpi_translation_cache_init(kvm);
> +
> + /*
> + * If we have GICv4.1 enabled, unconditionnaly request enable the
> + * v4 support so that we get HW-accelerated vSGIs. Otherwise, only
> + * enable it if we present a virtual ITS to the guest.
> + */
> + if (vgic_supports_direct_msis(kvm)) {
> ret = vgic_v4_init(kvm);
> if (ret)
> goto out;
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index e72dcc4542475..26b11dcd45524 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -50,7 +50,8 @@ bool vgic_has_its(struct kvm *kvm)
>
> bool vgic_supports_direct_msis(struct kvm *kvm)
> {
> - return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
> + return (kvm_vgic_global_state.has_gicv4_1 ||
> + (kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm)));
> }
Not related to this patch, but I think that the function name can be
improved a bit after this change. It now indicates whether the vGIC
supports direct MSIs injection *or* direct SGIs injection, not just
MSIs. And if vgic_has_its() is false, we don't even support MSIs.
The fix itself looks correct to me,
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Thanks.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] KVM: arm64: vgic-v4: Initialize GICv4.1 even in the absence of a virtual ITS
@ 2020-04-30 11:24 ` Zenghui Yu
0 siblings, 0 replies; 9+ messages in thread
From: Zenghui Yu @ 2020-04-30 11:24 UTC (permalink / raw)
To: Marc Zyngier, linux-arm-kernel, kvm, kvmarm
Hi Marc,
On 2020/4/25 17:44, Marc Zyngier wrote:
> KVM now expects to be able to use HW-accelerated delivery of vSGIs
> as soon as the guest has enabled thm. Unfortunately, we only
them
> initialize the GICv4 context if we have a virtual ITS exposed to
> the guest.
>
> Fix it by always initializing the GICv4.1 context if it is
> available on the host.
>
> Fixes: 2291ff2f2a56 ("KVM: arm64: GICv4.1: Plumb SGI implementation selection in the distributor")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> virt/kvm/arm/vgic/vgic-init.c | 9 ++++++++-
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 ++-
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index a963b9d766b73..8e6f350c3bcd1 100644
> --- a/virt/kvm/arm/vgic/vgic-init.c
> +++ b/virt/kvm/arm/vgic/vgic-init.c
> @@ -294,8 +294,15 @@ int vgic_init(struct kvm *kvm)
> }
> }
>
> - if (vgic_has_its(kvm)) {
> + if (vgic_has_its(kvm))
> vgic_lpi_translation_cache_init(kvm);
> +
> + /*
> + * If we have GICv4.1 enabled, unconditionnaly request enable the
> + * v4 support so that we get HW-accelerated vSGIs. Otherwise, only
> + * enable it if we present a virtual ITS to the guest.
> + */
> + if (vgic_supports_direct_msis(kvm)) {
> ret = vgic_v4_init(kvm);
> if (ret)
> goto out;
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index e72dcc4542475..26b11dcd45524 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -50,7 +50,8 @@ bool vgic_has_its(struct kvm *kvm)
>
> bool vgic_supports_direct_msis(struct kvm *kvm)
> {
> - return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
> + return (kvm_vgic_global_state.has_gicv4_1 ||
> + (kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm)));
> }
Not related to this patch, but I think that the function name can be
improved a bit after this change. It now indicates whether the vGIC
supports direct MSIs injection *or* direct SGIs injection, not just
MSIs. And if vgic_has_its() is false, we don't even support MSIs.
The fix itself looks correct to me,
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Thanks.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] KVM: arm64: vgic-v4: Initialize GICv4.1 even in the absence of a virtual ITS
2020-04-30 11:24 ` Zenghui Yu
(?)
@ 2020-04-30 11:39 ` Marc Zyngier
-1 siblings, 0 replies; 9+ messages in thread
From: Marc Zyngier @ 2020-04-30 11:39 UTC (permalink / raw)
To: Zenghui Yu
Cc: linux-arm-kernel, kvm, kvmarm, James Morse, Julien Thierry,
Suzuki K Poulose, Eric Auger
Hi Zenghui,
On 2020-04-30 12:24, Zenghui Yu wrote:
> Hi Marc,
>
> On 2020/4/25 17:44, Marc Zyngier wrote:
>> KVM now expects to be able to use HW-accelerated delivery of vSGIs
>> as soon as the guest has enabled thm. Unfortunately, we only
> them
>> initialize the GICv4 context if we have a virtual ITS exposed to
>> the guest.
>>
>> Fix it by always initializing the GICv4.1 context if it is
>> available on the host.
>>
>> Fixes: 2291ff2f2a56 ("KVM: arm64: GICv4.1: Plumb SGI implementation
>> selection in the distributor")
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>> ---
>> virt/kvm/arm/vgic/vgic-init.c | 9 ++++++++-
>> virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 ++-
>> 2 files changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-init.c
>> b/virt/kvm/arm/vgic/vgic-init.c
>> index a963b9d766b73..8e6f350c3bcd1 100644
>> --- a/virt/kvm/arm/vgic/vgic-init.c
>> +++ b/virt/kvm/arm/vgic/vgic-init.c
>> @@ -294,8 +294,15 @@ int vgic_init(struct kvm *kvm)
>> }
>> }
>> - if (vgic_has_its(kvm)) {
>> + if (vgic_has_its(kvm))
>> vgic_lpi_translation_cache_init(kvm);
>> +
>> + /*
>> + * If we have GICv4.1 enabled, unconditionnaly request enable the
>> + * v4 support so that we get HW-accelerated vSGIs. Otherwise, only
>> + * enable it if we present a virtual ITS to the guest.
>> + */
>> + if (vgic_supports_direct_msis(kvm)) {
>> ret = vgic_v4_init(kvm);
>> if (ret)
>> goto out;
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> index e72dcc4542475..26b11dcd45524 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> @@ -50,7 +50,8 @@ bool vgic_has_its(struct kvm *kvm)
>> bool vgic_supports_direct_msis(struct kvm *kvm)
>> {
>> - return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
>> + return (kvm_vgic_global_state.has_gicv4_1 ||
>> + (kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm)));
>> }
>
> Not related to this patch, but I think that the function name can be
> improved a bit after this change. It now indicates whether the vGIC
> supports direct MSIs injection *or* direct SGIs injection, not just
> MSIs. And if vgic_has_its() is false, we don't even support MSIs.
Yes, I noticed that too. But in the spirit of keeping the change minimal
and avoid later conflicts with potential fixes, I decided against
changing
it right now.
> The fix itself looks correct to me,
>
> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] KVM: arm64: vgic-v4: Initialize GICv4.1 even in the absence of a virtual ITS
@ 2020-04-30 11:39 ` Marc Zyngier
0 siblings, 0 replies; 9+ messages in thread
From: Marc Zyngier @ 2020-04-30 11:39 UTC (permalink / raw)
To: Zenghui Yu
Cc: kvm, Suzuki K Poulose, Eric Auger, James Morse, linux-arm-kernel,
kvmarm, Julien Thierry
Hi Zenghui,
On 2020-04-30 12:24, Zenghui Yu wrote:
> Hi Marc,
>
> On 2020/4/25 17:44, Marc Zyngier wrote:
>> KVM now expects to be able to use HW-accelerated delivery of vSGIs
>> as soon as the guest has enabled thm. Unfortunately, we only
> them
>> initialize the GICv4 context if we have a virtual ITS exposed to
>> the guest.
>>
>> Fix it by always initializing the GICv4.1 context if it is
>> available on the host.
>>
>> Fixes: 2291ff2f2a56 ("KVM: arm64: GICv4.1: Plumb SGI implementation
>> selection in the distributor")
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>> ---
>> virt/kvm/arm/vgic/vgic-init.c | 9 ++++++++-
>> virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 ++-
>> 2 files changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-init.c
>> b/virt/kvm/arm/vgic/vgic-init.c
>> index a963b9d766b73..8e6f350c3bcd1 100644
>> --- a/virt/kvm/arm/vgic/vgic-init.c
>> +++ b/virt/kvm/arm/vgic/vgic-init.c
>> @@ -294,8 +294,15 @@ int vgic_init(struct kvm *kvm)
>> }
>> }
>> - if (vgic_has_its(kvm)) {
>> + if (vgic_has_its(kvm))
>> vgic_lpi_translation_cache_init(kvm);
>> +
>> + /*
>> + * If we have GICv4.1 enabled, unconditionnaly request enable the
>> + * v4 support so that we get HW-accelerated vSGIs. Otherwise, only
>> + * enable it if we present a virtual ITS to the guest.
>> + */
>> + if (vgic_supports_direct_msis(kvm)) {
>> ret = vgic_v4_init(kvm);
>> if (ret)
>> goto out;
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> index e72dcc4542475..26b11dcd45524 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> @@ -50,7 +50,8 @@ bool vgic_has_its(struct kvm *kvm)
>> bool vgic_supports_direct_msis(struct kvm *kvm)
>> {
>> - return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
>> + return (kvm_vgic_global_state.has_gicv4_1 ||
>> + (kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm)));
>> }
>
> Not related to this patch, but I think that the function name can be
> improved a bit after this change. It now indicates whether the vGIC
> supports direct MSIs injection *or* direct SGIs injection, not just
> MSIs. And if vgic_has_its() is false, we don't even support MSIs.
Yes, I noticed that too. But in the spirit of keeping the change minimal
and avoid later conflicts with potential fixes, I decided against
changing
it right now.
> The fix itself looks correct to me,
>
> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] KVM: arm64: vgic-v4: Initialize GICv4.1 even in the absence of a virtual ITS
@ 2020-04-30 11:39 ` Marc Zyngier
0 siblings, 0 replies; 9+ messages in thread
From: Marc Zyngier @ 2020-04-30 11:39 UTC (permalink / raw)
To: Zenghui Yu; +Cc: kvm, linux-arm-kernel, kvmarm
Hi Zenghui,
On 2020-04-30 12:24, Zenghui Yu wrote:
> Hi Marc,
>
> On 2020/4/25 17:44, Marc Zyngier wrote:
>> KVM now expects to be able to use HW-accelerated delivery of vSGIs
>> as soon as the guest has enabled thm. Unfortunately, we only
> them
>> initialize the GICv4 context if we have a virtual ITS exposed to
>> the guest.
>>
>> Fix it by always initializing the GICv4.1 context if it is
>> available on the host.
>>
>> Fixes: 2291ff2f2a56 ("KVM: arm64: GICv4.1: Plumb SGI implementation
>> selection in the distributor")
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>> ---
>> virt/kvm/arm/vgic/vgic-init.c | 9 ++++++++-
>> virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 ++-
>> 2 files changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-init.c
>> b/virt/kvm/arm/vgic/vgic-init.c
>> index a963b9d766b73..8e6f350c3bcd1 100644
>> --- a/virt/kvm/arm/vgic/vgic-init.c
>> +++ b/virt/kvm/arm/vgic/vgic-init.c
>> @@ -294,8 +294,15 @@ int vgic_init(struct kvm *kvm)
>> }
>> }
>> - if (vgic_has_its(kvm)) {
>> + if (vgic_has_its(kvm))
>> vgic_lpi_translation_cache_init(kvm);
>> +
>> + /*
>> + * If we have GICv4.1 enabled, unconditionnaly request enable the
>> + * v4 support so that we get HW-accelerated vSGIs. Otherwise, only
>> + * enable it if we present a virtual ITS to the guest.
>> + */
>> + if (vgic_supports_direct_msis(kvm)) {
>> ret = vgic_v4_init(kvm);
>> if (ret)
>> goto out;
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> index e72dcc4542475..26b11dcd45524 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> @@ -50,7 +50,8 @@ bool vgic_has_its(struct kvm *kvm)
>> bool vgic_supports_direct_msis(struct kvm *kvm)
>> {
>> - return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
>> + return (kvm_vgic_global_state.has_gicv4_1 ||
>> + (kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm)));
>> }
>
> Not related to this patch, but I think that the function name can be
> improved a bit after this change. It now indicates whether the vGIC
> supports direct MSIs injection *or* direct SGIs injection, not just
> MSIs. And if vgic_has_its() is false, we don't even support MSIs.
Yes, I noticed that too. But in the spirit of keeping the change minimal
and avoid later conflicts with potential fixes, I decided against
changing
it right now.
> The fix itself looks correct to me,
>
> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 9+ messages in thread