From: Roman Bolshakov <roman@roolebo.dev>
To: Phil Dennis-Jordan <phil@philjordan.eu>
Cc: qemu-devel@nongnu.org, dirty@apple.com, rbolshakov@ddn.com,
lists@philjordan.eu
Subject: Re: [PATCH 2/3] i386: hvf: In kick_vcpu use hv_vcpu_interrupt to force exit
Date: Sun, 8 Oct 2023 21:23:39 +0300 [thread overview]
Message-ID: <ZSLzq33DgMNYBsQT@roolebo.dev> (raw)
In-Reply-To: <20230922140914.13906-3-phil@philjordan.eu>
On Fri, Sep 22, 2023 at 04:09:13PM +0200, Phil Dennis-Jordan wrote:
> When interrupting a vCPU thread, this patch actually tells the hypervisor to
> stop running guest code on that vCPU.
>
> Calling hv_vcpu_interrupt actually forces a vCPU exit, analogously to
> hv_vcpus_exit on aarch64.
>
> Previously, hvf_kick_vcpu_thread relied upon hv_vcpu_run returning very
> frequently, including many spurious exits, which made it less of a problem that
> nothing was actively done to stop the vCPU thread running guest code.
> The newer, more efficient hv_vcpu_run_until exits much more rarely, so a true
> "kick" is needed.
>
Hi Phil,
I see severe performance regression with the patch on a Windows XP
guest. The display is not refreshed properly like a broken LVDS panel,
only some horizontal lines appear on it. My test laptop for x86 hvf is
MBA 2015 with the latest Big Sur. What are you runing QEMU/HVF on?
FWIW. I recall a few years ago I submitted a similar patch that does
something similar but addresses a few more issues:
https://patchwork.kernel.org/project/qemu-devel/patch/20200729124832.79375-1-r.bolshakov@yadro.com/
I don't remember why it never got merged.
Regards,
Roman
next prev parent reply other threads:[~2023-10-08 18:24 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-22 14:09 [PATCH 0/3] hvf x86 correctness and efficiency improvements Phil Dennis-Jordan
2023-09-22 14:09 ` [PATCH 1/3] i386: hvf: Adds support for INVTSC cpuid bit Phil Dennis-Jordan
2023-10-08 18:07 ` Roman Bolshakov
2023-09-22 14:09 ` [PATCH 2/3] i386: hvf: In kick_vcpu use hv_vcpu_interrupt to force exit Phil Dennis-Jordan
2023-10-08 18:23 ` Roman Bolshakov [this message]
2023-10-08 18:39 ` Phil Dennis-Jordan
2023-10-08 19:19 ` Roman Bolshakov
2023-10-08 19:29 ` Phil Dennis-Jordan
2023-10-16 14:19 ` Phil Dennis-Jordan
2023-10-20 15:12 ` Phil Dennis-Jordan
2023-11-05 15:21 ` Roman Bolshakov
2023-11-06 14:15 ` Phil Dennis-Jordan
2023-09-22 14:09 ` [PATCH 3/3] i386: hvf: Updates API usage to use modern vCPU run function Phil Dennis-Jordan
2023-10-05 20:30 ` [PATCH 0/3] hvf x86 correctness and efficiency improvements Phil Dennis-Jordan
2023-10-16 14:39 ` Paolo Bonzini
2023-10-16 16:45 ` Phil Dennis-Jordan
2023-10-16 16:48 ` Paolo Bonzini
2023-10-16 20:05 ` Phil Dennis-Jordan
2023-10-16 21:08 ` Paolo Bonzini
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