From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Cc: James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Oliver Upton <oliver.upton@linux.dev>,
Zenghui Yu <yuzenghui@huawei.com>,
Ricardo Koller <ricarkol@google.com>,
Simon Veith <sveith@amazon.de>,
Reiji Watanabe <reijiw@google.com>,
Colton Lewis <coltonlewis@google.com>,
Joey Gouly <joey.gouly@arm.com>,
dwmw2@infradead.org
Subject: [PATCH v3 01/18] KVM: arm64: timers: Use a per-vcpu, per-timer accumulator for fractional ns
Date: Fri, 24 Mar 2023 14:46:47 +0000 [thread overview]
Message-ID: <20230324144704.4193635-2-maz@kernel.org> (raw)
In-Reply-To: <20230324144704.4193635-1-maz@kernel.org>
Instead of accumulating the fractional ns value generated every time
we compute a ns delta in a global variable, use a per-vcpu, per-timer
variable. This keeps the fractional ns local to the timer instead of
contributing to any odd, unrelated timer.
Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/arch_timer.c | 2 +-
include/kvm/arm_arch_timer.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index e1af4301b913..9515c645f03d 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -212,7 +212,7 @@ static u64 kvm_counter_compute_delta(struct arch_timer_context *timer_ctx,
ns = cyclecounter_cyc2ns(timecounter->cc,
val - now,
timecounter->mask,
- &timecounter->frac);
+ &timer_ctx->ns_frac);
return ns;
}
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index c52a6e6839da..70d47c4adc6a 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -44,6 +44,7 @@ struct arch_timer_context {
/* Emulated Timer (may be unused) */
struct hrtimer hrtimer;
+ u64 ns_frac;
/* Offset for this counter/timer */
struct arch_timer_offset offset;
--
2.34.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2023-03-24 14:48 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-24 14:46 [PATCH v3 00/18] KVM: arm64: Rework timer offsetting for fun and profit Marc Zyngier
2023-03-24 14:46 ` Marc Zyngier [this message]
2023-03-24 14:46 ` [PATCH v3 02/18] arm64: Add CNTPOFF_EL2 register definition Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 03/18] arm64: Add HAS_ECV_CNTPOFF capability Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 04/18] KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 05/18] KVM: arm64: timers: Allow physical offset without CNTPOFF_EL2 Marc Zyngier
2023-03-30 6:42 ` Oliver Upton
2023-03-30 10:09 ` Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 06/18] KVM: arm64: Expose {un,}lock_all_vcpus() to the rest of KVM Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 07/18] KVM: arm64: timers: Allow userspace to set the global counter offset Marc Zyngier
2023-03-30 6:26 ` Oliver Upton
2023-03-30 10:15 ` Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 08/18] KVM: arm64: timers: Allow save/restoring of the physical timer Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 09/18] KVM: arm64: timers: Rationalise per-vcpu timer init Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 10/18] KVM: arm64: timers: Abstract per-timer IRQ access Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 11/18] KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data Marc Zyngier
2023-03-30 7:02 ` Oliver Upton
2023-03-30 10:19 ` Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 12/18] KVM: arm64: Abstract the number of valid timers per vcpu Marc Zyngier
2023-03-24 14:46 ` [PATCH v3 13/18] KVM: arm64: Document KVM_ARM_SET_CNT_OFFSETS and co Marc Zyngier
2023-03-24 14:47 ` [PATCH v3 14/18] KVM: arm64: nv: timers: Add a per-timer, per-vcpu offset Marc Zyngier
2023-03-24 14:47 ` [PATCH v3 15/18] KVM: arm64: nv: timers: Support hyp timer emulation Marc Zyngier
2023-03-24 14:47 ` [PATCH v3 16/18] KVM: arm64: selftests: Add physical timer registers to the sysreg list Marc Zyngier
2023-03-24 14:47 ` [PATCH v3 17/18] KVM: arm64: selftests: Deal with spurious timer interrupts Marc Zyngier
2023-03-24 14:47 ` [PATCH v3 18/18] KVM: arm64: selftests: Augment existing timer test to handle variable offset Marc Zyngier
2023-03-29 5:41 ` [PATCH v3 00/18] KVM: arm64: Rework timer offsetting for fun and profit Veith, Simon
2023-03-30 17:46 ` Marc Zyngier
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=20230324144704.4193635-2-maz@kernel.org \
--to=maz@kernel.org \
--cc=coltonlewis@google.com \
--cc=dwmw2@infradead.org \
--cc=james.morse@arm.com \
--cc=joey.gouly@arm.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=oliver.upton@linux.dev \
--cc=reijiw@google.com \
--cc=ricarkol@google.com \
--cc=suzuki.poulose@arm.com \
--cc=sveith@amazon.de \
--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).