On 06/29/21 12:35, Andrew Cooper wrote: > On 29/06/2021 11:07, Jan Beulich wrote: >> On 29.06.2021 11:20, Laszlo Ersek wrote: >>> On 06/28/21 15:23, Anthony PERARD via groups.io wrote: >>>> From: Anthony PERARD <anthony.per...@citrix.com> >>>> >>>> Unfortunately, Xen isn't ready to deal with mapping at the top of the >>>> physical address space, so we relocate the mapping after the LAPIC >>>> location. >>>> >>>> See this thread about the issue with the mapping: >>>> - >>>> https://lore.kernel.org/xen-devel/f8c4151a-6dac-d87c-ef46-eb35ada07...@suse.com/ >>>> >>>> The PhysicalAddressIdentityMapping() call isn't going to do anything >>>> anymore since everything under 4GB is already mapped, but there is no >>>> need to remove the call. >>>> >>>> CC: Jan Beulich <jbeul...@suse.com> >>>> CC: Andrew Cooper <andrew.coop...@citrix.com> >>>> Signed-off-by: Anthony PERARD <anthony.per...@citrix.com> >>>> --- >>>> OvmfPkg/XenPlatformPei/Xen.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/OvmfPkg/XenPlatformPei/Xen.c b/OvmfPkg/XenPlatformPei/Xen.c >>>> index a4e82b356936..9c6641895970 100644 >>>> --- a/OvmfPkg/XenPlatformPei/Xen.c >>>> +++ b/OvmfPkg/XenPlatformPei/Xen.c >>>> @@ -569,7 +569,7 @@ CalibrateLapicTimer ( >>>> EFI_STATUS Status; >>>> >>>> >>>> - SharedInfo = (VOID*)((1ULL << mPhysMemAddressWidth) - EFI_PAGE_SIZE); >>>> + SharedInfo = (VOID*)((UINTN)PcdGet32 (PcdCpuLocalApicBaseAddress) + >>>> SIZE_1MB); >>>> Status = PhysicalAddressIdentityMapping >>>> ((EFI_PHYSICAL_ADDRESS)SharedInfo); >>>> if (EFI_ERROR (Status)) { >>>> DEBUG ((DEBUG_ERROR, >>>> >>> Acked-by: Laszlo Ersek <ler...@redhat.com> >>> >>> I guess I should merge this after Jan and/or Andrew ack it. >> Well, I can informally ack that a move like this is needed, but I can't >> really give an Acked-by on the change, as I know next to nothing about >> ovmf, and hence I cannot, for example, tell whether the chosen new >> location is okay to use there. > > That bit is easy, although it probably does warrant a code comment. The > choice of location doesn't matter specifically (so long as it's not too > high for 32bit toolstacks to cope with), but wants to be something which > isn't RAM, and ideally doesn't shatter a superpage. > > The various MMIO ranges (IO-APIC, TPM, LAPIC) are 2M aligned, so LAPIC + > 1M is firmly in the middle of a range not used by anything else, and > with APICV/AVIC, the LAPIC does have a 4k mapping to the sink page.
I'm OK with informal ACKs of course, just please let me know when you guys feel it's OK for me to merge the patch. I saw the CCs and so I didn't want to hasten and merge the patch before you could object. Thanks Laszlo -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#77266): https://edk2.groups.io/g/devel/message/77266 Mute This Topic: https://groups.io/mt/83844392/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
