KVM ARM Archive on lore.kernel.org
 help / color / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: Will Deacon <will@kernel.org>
Subject: [PATCH v2 0/5] KVM: arm64: Assorted PMU emulation fixes
Date: Tue,  8 Oct 2019 17:01:23 +0100
Message-ID: <20191008160128.8872-1-maz@kernel.org> (raw)

I recently came across a number of PMU emulation bugs, all which can
result in unexpected behaviours in an unsuspecting guest. The first
two patches already have been discussed on the list, but I'm including
them here as part of a slightly longer series.

The third patch is new as of v2, and fixes a bug preventing chained
events from ever being used.

The fourth patch is also new as of v2, and is an arm64 PMU change for
which I clearly don't know what I'm doing. I'd appreciate some
guidance from Will or Mark.

The last patch fixes an issue that has been here from day one, where
we confuse architectural overflow of a counter and perf sampling
period, and uses patch #4 to fix the issue.

I'l planning to send patches 1 through to 3 as fixes shortly, but I
expect the last two patches to require more discussions.

Marc Zyngier (5):
  KVM: arm64: pmu: Fix cycle counter truncation
  arm64: KVM: Handle PMCR_EL0.LC as RES1 on pure AArch64 systems
  KVM: arm64: pmu: Set the CHAINED attribute before creating the
    in-kernel event
  arm64: perf: Add reload-on-overflow capability
  KVM: arm64: pmu: Reset sample period on overflow handling

 arch/arm64/include/asm/perf_event.h |  4 +++
 arch/arm64/kernel/perf_event.c      |  8 ++++-
 arch/arm64/kvm/sys_regs.c           |  4 +++
 virt/kvm/arm/pmu.c                  | 45 +++++++++++++++++++----------
 4 files changed, 45 insertions(+), 16 deletions(-)

-- 
2.20.1

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

             reply index

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-08 16:01 Marc Zyngier [this message]
2019-10-08 16:01 ` [PATCH v2 1/5] KVM: arm64: pmu: Fix cycle counter truncation Marc Zyngier
2019-10-08 16:01 ` [PATCH v2 2/5] arm64: KVM: Handle PMCR_EL0.LC as RES1 on pure AArch64 systems Marc Zyngier
2019-10-08 16:01 ` [PATCH v2 3/5] KVM: arm64: pmu: Set the CHAINED attribute before creating the in-kernel event Marc Zyngier
2019-10-08 19:22   ` Andrew Murray
2019-10-08 16:01 ` [PATCH v2 4/5] arm64: perf: Add reload-on-overflow capability Marc Zyngier
2019-10-08 17:55   ` Marc Zyngier
2019-10-08 19:52   ` Andrew Murray
2019-10-08 16:01 ` [PATCH v2 5/5] KVM: arm64: pmu: Reset sample period on overflow handling Marc Zyngier
2019-10-08 22:42   ` Andrew Murray
2019-10-11 11:28     ` Marc Zyngier
2019-10-11 11:41       ` Andrew Murray

Reply instructions:

You may reply publically 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=20191008160128.8872-1-maz@kernel.org \
    --to=maz@kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=will@kernel.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

KVM ARM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/kvmarm/0 kvmarm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 kvmarm kvmarm/ https://lore.kernel.org/kvmarm \
		kvmarm@lists.cs.columbia.edu
	public-inbox-index kvmarm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/edu.columbia.cs.lists.kvmarm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git