On 29.06.2021 13:29, Laszlo Ersek wrote: > 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.
I think you are fine going ahead as long as from the ovmf side all is good here. Jan -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#77269): https://edk2.groups.io/g/devel/message/77269 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] -=-=-=-=-=-=-=-=-=-=-=-
