From: "Gerd Hoffmann" <kraxel@redhat.com>
To: "Xu, Min M" <min.m.xu@intel.com>
Cc: "Ni, Ray" <ray.ni@intel.com>,
"devel@edk2.groups.io" <devel@edk2.groups.io>,
Rebecca Cran <rebecca@bsdio.com>,
Peter Grehan <grehan@freebsd.org>,
Tom Lendacky <thomas.lendacky@amd.com>,
Anthony Perard <anthony.perard@citrix.com>,
"Yao, Jiewen" <jiewen.yao@intel.com>,
"Dong, Eric" <eric.dong@intel.com>
Subject: Re: [PATCH V3 3/3] OvmfPkg: Move LocalApicTimerDxe to UefiCpuPkg
Date: Tue, 23 Nov 2021 10:45:17 +0100 [thread overview]
Message-ID: <20211123094517.sja253rzqxaizh36@sirius.home.kraxel.org> (raw)
In-Reply-To: <PH0PR11MB50648D995EE0B4EB5CD8085DC5609@PH0PR11MB5064.namprd11.prod.outlook.com>
Hi,
> > 2. Can SourceLevelDebug (rely on Local APIC timer) work if this driver is
> > chosen as DXE timer driver?
> After checking the code and running the PoC (enable SourceLevelDebug and LocalApicTimerDxe), I find this driver doesn't work anymore.
> Actually it asserts in https://github.com/mxu9/edk2/blob/ovmf_lapic_timer.v3/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.c#L334
Hmm, I guess this makes LocalApicTimerDxe alot less useful on physical
hardware. So keep it in OvmdPkg?
For virtual machines there are other debugging options, using qemu's
builtin gdb server for example, so SourceLevelDebug not being available
isn't a big issue IMHO.
> For TDVF we assume SourceLevelDebug is not supported. So LocalApicTimerDxe is still working for TDVF.
>
> For other VM guests in OvmfPkg, can we assume SourceLevelDebug is NOT supported after LocalApicTimer is used (the older timer is 8254)?
> @ Gerd Hoffmann (OvmfPkg)
Fine with me.
> @ Anthony Perard , Julien Grall (Xen)
Xen already uses the apic timer today, so that shouldn't be a problem
either ;)
take care,
Gerd
next prev parent reply other threads:[~2021-11-23 9:45 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-08 6:07 [PATCH V3 0/3] Rename XenTimerDxe to LocalApicTimerDxe Min Xu
2021-11-08 6:07 ` [PATCH V3 1/3] OvmfPkg: " Min Xu
2021-11-11 14:46 ` Anthony PERARD
2021-11-08 6:07 ` [PATCH V3 2/3] OvmfPkg: Switch timer in build time for OvmfPkg Min Xu
2021-11-08 6:08 ` [PATCH V3 3/3] OvmfPkg: Move LocalApicTimerDxe to UefiCpuPkg Min Xu
2021-11-11 14:47 ` Anthony PERARD
2021-11-22 3:04 ` Ni, Ray
2021-11-22 3:34 ` Yao, Jiewen
2021-11-23 8:24 ` Min Xu
2021-11-23 9:45 ` Gerd Hoffmann [this message]
2021-11-09 6:59 ` [PATCH V3 0/3] Rename XenTimerDxe to LocalApicTimerDxe Gerd Hoffmann
2021-11-09 7:03 ` Yao, Jiewen
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