All of lore.kernel.org
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org
Subject: Re: [PATCH 5/8] KVM: arm64: Remove PMU RAZ/WI handling
Date: Fri, 27 Nov 2020 08:50:02 +0000	[thread overview]
Message-ID: <7ae93087a57bd5f6a348f0d4d6a7db2d@kernel.org> (raw)
In-Reply-To: <cb7ebedb-5525-8493-007f-72c81b16189b@arm.com>

On 2020-11-26 15:06, Alexandru Elisei wrote:
> Hi Marc,
> 
> This patch looks correct to me, I checked in the Arm ARM DDI 0487F.b 
> and indeed
> all accesses to the PMU registers are UNDEFINED if the PMU is not 
> present.
> 
> I checked all the accessors and now all the PMU registers that KVM 
> emulates will
> inject an undefined exception if the VCPU feature isn't set. There's
> one register
> that we don't emulate, PMMIR_EL1, I suppose that's because it's part of 
> PMU
> ARMv8.4 and KVM advertises ARMv8.1; if the guest tries to access it, it 
> will get
> an undefined exception and KVM will print a warning in 
> emulate_sys_reg().

Funny that. I wrote a patch for that a long while ago, and obviously
never did anything with it [1]... Actually, the whole series was 
silently
dropped. I guess I had other things to think about at the time!

Let me pick that up again.

> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>

Thanks!

         M.

[1] 
https://lore.kernel.org/kvmarm/20200216185324.32596-6-maz@kernel.org/
-- 
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org
Subject: Re: [PATCH 5/8] KVM: arm64: Remove PMU RAZ/WI handling
Date: Fri, 27 Nov 2020 08:50:02 +0000	[thread overview]
Message-ID: <7ae93087a57bd5f6a348f0d4d6a7db2d@kernel.org> (raw)
In-Reply-To: <cb7ebedb-5525-8493-007f-72c81b16189b@arm.com>

On 2020-11-26 15:06, Alexandru Elisei wrote:
> Hi Marc,
> 
> This patch looks correct to me, I checked in the Arm ARM DDI 0487F.b 
> and indeed
> all accesses to the PMU registers are UNDEFINED if the PMU is not 
> present.
> 
> I checked all the accessors and now all the PMU registers that KVM 
> emulates will
> inject an undefined exception if the VCPU feature isn't set. There's
> one register
> that we don't emulate, PMMIR_EL1, I suppose that's because it's part of 
> PMU
> ARMv8.4 and KVM advertises ARMv8.1; if the guest tries to access it, it 
> will get
> an undefined exception and KVM will print a warning in 
> emulate_sys_reg().

Funny that. I wrote a patch for that a long while ago, and obviously
never did anything with it [1]... Actually, the whole series was 
silently
dropped. I guess I had other things to think about at the time!

Let me pick that up again.

> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>

Thanks!

         M.

[1] 
https://lore.kernel.org/kvmarm/20200216185324.32596-6-maz@kernel.org/
-- 
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

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
	kernel-team@android.com
Subject: Re: [PATCH 5/8] KVM: arm64: Remove PMU RAZ/WI handling
Date: Fri, 27 Nov 2020 08:50:02 +0000	[thread overview]
Message-ID: <7ae93087a57bd5f6a348f0d4d6a7db2d@kernel.org> (raw)
In-Reply-To: <cb7ebedb-5525-8493-007f-72c81b16189b@arm.com>

On 2020-11-26 15:06, Alexandru Elisei wrote:
> Hi Marc,
> 
> This patch looks correct to me, I checked in the Arm ARM DDI 0487F.b 
> and indeed
> all accesses to the PMU registers are UNDEFINED if the PMU is not 
> present.
> 
> I checked all the accessors and now all the PMU registers that KVM 
> emulates will
> inject an undefined exception if the VCPU feature isn't set. There's
> one register
> that we don't emulate, PMMIR_EL1, I suppose that's because it's part of 
> PMU
> ARMv8.4 and KVM advertises ARMv8.1; if the guest tries to access it, it 
> will get
> an undefined exception and KVM will print a warning in 
> emulate_sys_reg().

Funny that. I wrote a patch for that a long while ago, and obviously
never did anything with it [1]... Actually, the whole series was 
silently
dropped. I guess I had other things to think about at the time!

Let me pick that up again.

> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>

Thanks!

         M.

[1] 
https://lore.kernel.org/kvmarm/20200216185324.32596-6-maz@kernel.org/
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2020-11-27  8:50 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-13 18:25 [PATCH 0/8] KVM: arm64: Disabled PMU handling Marc Zyngier
2020-11-13 18:25 ` Marc Zyngier
2020-11-13 18:25 ` Marc Zyngier
2020-11-13 18:25 ` [PATCH 1/8] KVM: arm64: Add kvm_vcpu_has_pmu() helper Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-13 18:25 ` [PATCH 2/8] KVM: arm64: Set ID_AA64DFR0_EL1.PMUVer to 0 when no PMU support Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-13 18:25 ` [PATCH 3/8] KVM: arm64: Refuse illegal KVM_ARM_VCPU_PMU_V3 at reset time Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-26 14:59   ` Alexandru Elisei
2020-11-26 14:59     ` Alexandru Elisei
2020-11-26 14:59     ` Alexandru Elisei
2020-11-26 15:25     ` Marc Zyngier
2020-11-26 15:25       ` Marc Zyngier
2020-11-26 15:25       ` Marc Zyngier
2020-11-26 15:49       ` Alexandru Elisei
2020-11-26 15:49         ` Alexandru Elisei
2020-11-26 15:49         ` Alexandru Elisei
2020-11-13 18:25 ` [PATCH 4/8] KVM: arm64: Inject UNDEF on PMU access when no PMU configured Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-13 18:25 ` [PATCH 5/8] KVM: arm64: Remove PMU RAZ/WI handling Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-13 18:25   ` Marc Zyngier
2020-11-26 15:06   ` Alexandru Elisei
2020-11-26 15:06     ` Alexandru Elisei
2020-11-26 15:06     ` Alexandru Elisei
2020-11-27  8:50     ` Marc Zyngier [this message]
2020-11-27  8:50       ` Marc Zyngier
2020-11-27  8:50       ` Marc Zyngier
2020-11-13 18:26 ` [PATCH 6/8] KVM: arm64: Remove dead PMU sysreg decoding code Marc Zyngier
2020-11-13 18:26   ` Marc Zyngier
2020-11-13 18:26   ` Marc Zyngier
2020-11-26 15:18   ` Alexandru Elisei
2020-11-26 15:18     ` Alexandru Elisei
2020-11-26 15:18     ` Alexandru Elisei
2020-11-26 15:34     ` Marc Zyngier
2020-11-26 15:34       ` Marc Zyngier
2020-11-26 15:34       ` Marc Zyngier
2020-11-26 15:54       ` Alexandru Elisei
2020-11-26 15:54         ` Alexandru Elisei
2020-11-26 15:54         ` Alexandru Elisei
2020-11-26 15:57         ` Marc Zyngier
2020-11-26 15:57           ` Marc Zyngier
2020-11-26 15:57           ` Marc Zyngier
2020-11-13 18:26 ` [PATCH 7/8] KVM: arm64: Gate kvm_pmu_update_state() on the PMU feature Marc Zyngier
2020-11-13 18:26   ` Marc Zyngier
2020-11-13 18:26   ` Marc Zyngier
2020-11-13 18:26 ` [PATCH 8/8] KVM: arm64: Get rid of the PMU ready state Marc Zyngier
2020-11-13 18:26   ` Marc Zyngier
2020-11-13 18:26   ` Marc Zyngier
2020-11-24 17:28 ` [PATCH 0/8] KVM: arm64: Disabled PMU handling Alexandru Elisei
2020-11-24 17:28   ` Alexandru Elisei
2020-11-24 17:28   ` Alexandru Elisei
2020-11-25  8:39   ` Marc Zyngier
2020-11-25  8:39     ` Marc Zyngier
2020-11-25  8:39     ` Marc Zyngier
2020-11-26 16:34 ` Alexandru Elisei
2020-11-26 16:34   ` Alexandru Elisei
2020-11-26 16:34   ` Alexandru Elisei

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=7ae93087a57bd5f6a348f0d4d6a7db2d@kernel.org \
    --to=maz@kernel.org \
    --cc=alexandru.elisei@arm.com \
    --cc=kernel-team@android.com \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.