From: Oliver Upton <oliver.upton@linux.dev>
To: Raghavendra Rao Ananta <rananta@google.com>
Cc: Marc Zyngier <maz@kernel.org>,
Alexandru Elisei <alexandru.elisei@arm.com>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Shaoqin Huang <shahuang@redhat.com>,
Jing Zhang <jingzhangos@google.com>,
Reiji Watanabe <reijiw@google.com>,
Colton Lewis <coltonlewis@google.com>,
linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH v7 02/12] KVM: arm64: PMU: Set the default PMU for the guest before vCPU reset
Date: Tue, 10 Oct 2023 22:25:48 +0000 [thread overview]
Message-ID: <ZSXPbKH519uWXytf@linux.dev> (raw)
In-Reply-To: <20231009230858.3444834-3-rananta@google.com>
Hi Raghu,
On Mon, Oct 09, 2023 at 11:08:48PM +0000, Raghavendra Rao Ananta wrote:
> From: Reiji Watanabe <reijiw@google.com>
>
> The following patches will use the number of counters information
> from the arm_pmu and use this to set the PMCR.N for the guest
> during vCPU reset. However, since the guest is not associated
> with any arm_pmu until userspace configures the vPMU device
> attributes, and a reset can happen before this event, assign a
> default PMU to the guest just before doing the reset.
>
> Signed-off-by: Reiji Watanabe <reijiw@google.com>
> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> ---
> arch/arm64/kvm/arm.c | 20 ++++++++++++++++++++
> arch/arm64/kvm/pmu-emul.c | 12 ++----------
> include/kvm/arm_pmu.h | 6 ++++++
> 3 files changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 78b0970eb8e6..708a53b70a7b 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1313,6 +1313,23 @@ static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu,
> KVM_VCPU_MAX_FEATURES);
> }
>
> +static int kvm_vcpu_set_pmu(struct kvm_vcpu *vcpu)
> +{
> + struct kvm *kvm = vcpu->kvm;
> +
> + if (!kvm_arm_support_pmu_v3())
> + return -EINVAL;
This check is pointless; the vCPU feature flags have been sanitised at
this point, and a requirement of having PMUv3 is that this predicate is
true.
> + /*
> + * When the vCPU has a PMU, but no PMU is set for the guest
> + * yet, set the default one.
> + */
> + if (unlikely(!kvm->arch.arm_pmu))
> + return kvm_arm_set_default_pmu(kvm);
> +
> + return 0;
> +}
> +
Apologies, I believe I was unclear last time around as to what I was
wanting here. Let's call this thing kvm_setup_vcpu() such that we can
add other one-time setup activities to it in the future.
Something like:
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 96641e442039..4896a44108e0 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1265,19 +1265,17 @@ static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu,
KVM_VCPU_MAX_FEATURES);
}
-static int kvm_vcpu_set_pmu(struct kvm_vcpu *vcpu)
+static int kvm_setup_vcpu(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
- if (!kvm_arm_support_pmu_v3())
- return -EINVAL;
-
/*
* When the vCPU has a PMU, but no PMU is set for the guest
* yet, set the default one.
*/
- if (unlikely(!kvm->arch.arm_pmu))
- return kvm_arm_set_default_pmu(kvm);
+ if (kvm_vcpu_has_pmu(vcpu) && !kvm->arch.arm_pmu &&
+ kvm_arm_set_default_pmu(kvm))
+ return -EINVAL;
return 0;
}
@@ -1297,7 +1295,8 @@ static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES);
- if (kvm_vcpu_has_pmu(vcpu) && kvm_vcpu_set_pmu(vcpu))
+ ret = kvm_setup_vcpu(vcpu);
+ if (ret)
goto out_unlock;
/* Now we know what it is, we can reset it. */
--
Thanks,
Oliver
next prev parent reply other threads:[~2023-10-10 22:26 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-09 23:08 [PATCH v7 00/12] KVM: arm64: PMU: Allow userspace to limit the number of PMCs on vCPU Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 01/12] KVM: arm64: PMU: Introduce helpers to set the guest's PMU Raghavendra Rao Ananta
2023-10-16 19:45 ` Eric Auger
2023-10-09 23:08 ` [PATCH v7 02/12] KVM: arm64: PMU: Set the default PMU for the guest before vCPU reset Raghavendra Rao Ananta
2023-10-10 22:25 ` Oliver Upton [this message]
2023-10-13 20:27 ` Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 03/12] KVM: arm64: PMU: Clear PM{C,I}NTEN{SET,CLR} and PMOVS{SET,CLR} on " Raghavendra Rao Ananta
2023-10-16 19:44 ` Eric Auger
2023-10-16 21:28 ` Raghavendra Rao Ananta
2023-10-17 9:23 ` Eric Auger
2023-10-17 16:59 ` Raghavendra Rao Ananta
2023-10-18 21:16 ` Raghavendra Rao Ananta
2023-10-18 22:17 ` Oliver Upton
2023-10-19 18:46 ` Raghavendra Rao Ananta
2023-10-19 19:05 ` Oliver Upton
2023-10-19 20:17 ` Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 04/12] KVM: arm64: PMU: Don't define the sysreg reset() for PM{USERENR,CCFILTR}_EL0 Raghavendra Rao Ananta
2023-10-16 19:47 ` Eric Auger
2023-10-09 23:08 ` [PATCH v7 05/12] KVM: arm64: PMU: Add a helper to read a vCPU's PMCR_EL0 Raghavendra Rao Ananta
2023-10-16 20:02 ` Eric Auger
2023-10-09 23:08 ` [PATCH v7 06/12] KVM: arm64: PMU: Add a helper to read the number of counters Raghavendra Rao Ananta
2023-10-10 22:30 ` Oliver Upton
2023-10-13 5:43 ` Oliver Upton
2023-10-13 20:24 ` Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 07/12] KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU Raghavendra Rao Ananta
2023-10-16 13:35 ` Sebastian Ott
2023-10-16 19:02 ` Raghavendra Rao Ananta
2023-10-16 19:15 ` Oliver Upton
2023-10-16 21:35 ` Raghavendra Rao Ananta
2023-10-17 5:52 ` Oliver Upton
2023-10-17 5:55 ` Oliver Upton
2023-10-17 16:58 ` Raghavendra Rao Ananta
2023-10-17 17:09 ` Oliver Upton
2023-10-17 17:25 ` Raghavendra Rao Ananta
2023-10-17 18:10 ` Oliver Upton
2023-10-17 18:45 ` Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 08/12] KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest Raghavendra Rao Ananta
2023-10-17 15:52 ` Sebastian Ott
2023-10-17 16:49 ` Raghavendra Rao Ananta
2023-10-19 10:45 ` Sebastian Ott
2023-10-19 18:05 ` Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 09/12] tools: Import arm_pmuv3.h Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 10/12] KVM: selftests: aarch64: Introduce vpmu_counter_access test Raghavendra Rao Ananta
2023-10-12 11:24 ` Sebastian Ott
2023-10-12 15:01 ` Sebastian Ott
2023-10-13 21:05 ` Raghavendra Rao Ananta
2023-10-16 10:01 ` Sebastian Ott
2023-10-16 18:56 ` Oliver Upton
2023-10-16 19:05 ` Raghavendra Rao Ananta
2023-10-16 19:07 ` Oliver Upton
2023-10-17 14:51 ` Eric Auger
2023-10-17 17:07 ` Raghavendra Rao Ananta
2023-10-17 15:48 ` Sebastian Ott
2023-10-17 17:10 ` Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 11/12] KVM: selftests: aarch64: vPMU register test for implemented counters Raghavendra Rao Ananta
2023-10-17 18:54 ` Eric Auger
2023-10-17 21:42 ` Raghavendra Rao Ananta
2023-10-09 23:08 ` [PATCH v7 12/12] KVM: selftests: aarch64: vPMU register test for unimplemented counters Raghavendra Rao Ananta
2023-10-18 6:54 ` Eric Auger
2023-10-19 18:09 ` Raghavendra Rao Ananta
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZSXPbKH519uWXytf@linux.dev \
--to=oliver.upton@linux.dev \
--cc=alexandru.elisei@arm.com \
--cc=coltonlewis@google.com \
--cc=james.morse@arm.com \
--cc=jingzhangos@google.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=pbonzini@redhat.com \
--cc=rananta@google.com \
--cc=reijiw@google.com \
--cc=shahuang@redhat.com \
--cc=suzuki.poulose@arm.com \
--cc=yuzenghui@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).