From: Paolo Bonzini <pbonzini@redhat.com>
To: Fiona Ebner <f.ebner@proxmox.com>
Cc: qemu-devel@nongnu.org, "Michael S . Tsirkin" <mst@redhat.com>
Subject: Re: [PULL 05/11] hpet: fix and cleanup persistence of interrupt status
Date: Wed, 19 Mar 2025 16:30:55 +0100 [thread overview]
Message-ID: <CABgObfaKJ5NFVKmYLFmu4C0iZZLJJtcWksLCzyA0tBoz0koZ4A@mail.gmail.com> (raw)
In-Reply-To: <8183674f-a9cc-4727-bb52-fe3d3e44804b@proxmox.com>
On Wed, Mar 19, 2025 at 4:29 PM Fiona Ebner <f.ebner@proxmox.com> wrote:
>
> Hi,
> If necessary, our management layer downstream could disable the hpet
> timer by default and make users explicitly enable it if
> desired/required. I just wanted to ask if the issue is known and if
> there are any other suggestions? Thanks!
We can try to skip the timer if the interrupt would have no change -
similar to how the RTC works, it's more complex but very effective in
reducing CPU usage.
That said, if you can disable the HPET timer by default without
problems with e.g. live migration I strongly suggest you do. And in
the mean time you can also revert these patches, they were actually
reported as bugs but it's not clear what guest OS was affected.
Paolo
next prev parent reply other threads:[~2025-03-19 15:31 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-23 14:15 [PULL 00/11] target/i386, HPET changes for QEMU 9.1 soft freeze Paolo Bonzini
2024-07-23 14:15 ` [PULL 01/11] target/i386: do not crash if microvm guest uses SGX CPUID leaves Paolo Bonzini
2024-07-23 14:15 ` [PULL 02/11] qio: add support for SO_PEERCRED for socket channel Paolo Bonzini
2024-07-23 14:15 ` [PULL 03/11] tools: build qemu-vmsr-helper Paolo Bonzini
2024-07-25 10:28 ` Peter Maydell
2024-07-25 10:30 ` Paolo Bonzini
2024-07-23 14:15 ` [PULL 04/11] Add support for RAPL MSRs in KVM/Qemu Paolo Bonzini
2024-07-25 10:25 ` Peter Maydell
2024-07-23 14:15 ` [PULL 05/11] hpet: fix and cleanup persistence of interrupt status Paolo Bonzini
2025-03-19 15:28 ` Fiona Ebner
2025-03-19 15:30 ` Paolo Bonzini [this message]
2025-03-19 15:47 ` Fiona Ebner
2025-03-19 15:51 ` Paolo Bonzini
2025-03-19 15:56 ` Fiona Ebner
2024-07-23 14:15 ` [PULL 06/11] hpet: ignore high bits of comparator in 32-bit mode Paolo Bonzini
2024-07-23 14:15 ` [PULL 07/11] hpet: remove unnecessary variable "index" Paolo Bonzini
2024-07-23 14:15 ` [PULL 08/11] hpet: place read-only bits directly in "new_val" Paolo Bonzini
2024-07-23 14:15 ` [PULL 09/11] hpet: accept 64-bit reads and writes Paolo Bonzini
2024-07-23 14:15 ` [PULL 10/11] hpet: store full 64-bit target value of the counter Paolo Bonzini
2024-07-23 14:15 ` [PULL 11/11] hpet: avoid timer storms on periodic timers Paolo Bonzini
2024-07-24 2:58 ` [PULL 00/11] target/i386, HPET changes for QEMU 9.1 soft freeze Richard Henderson
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