[edk2-devel] [PATCH v2 2/2] UefiCpuPkg: PiSmmCpuDxeSmm skip MSR_IA32_MISC_ENABLE manipulation on AMD
Laszlo Ersek
lersek at redhat.com
Fri Jun 19 14:48:24 UTC 2020
On 06/18/20 17:22, Kirkendall, Garrett wrote:
> AMD does not support MSR_IA32_MISC_ENABLE. Accessing that register
> causes and exception on AMD processors. If Execution Disable is
> supported, but if the processor is an AMD processor, skip manipulating
> MSR_IA32_MISC_ENABLE[34] XD Disable bit.
>
> Cc: Eric Dong <eric.dong at intel.com>
> Cc: Ray Ni <ray.ni at intel.com>
> Cc: Laszlo Ersek <lersek at redhat.com>
> Signed-off-by: Garrett Kirkendall <garrett.kirkendall at amd.com>
> ---
>
> Notes:
> Tested on Intel hardware with Laszlo Ersek's help
>
> (1) downloaded two Linux images from provided links.
> (2) Test using a 32-bit guest on an Intel host (standing in your edk2 tree, with the patches applied):
>
> $ build -a IA32 -b DEBUG -p OvmfPkg/OvmfPkgIa32.dsc -t GCC5 -D SMM_REQUIRE
>
> $ qemu-system-i386 \
> -cpu coreduo,-nx \
> -machine q35,smm=on,accel=kvm \
> -m 4096 \
> -smp 4 \
> -global driver=cfi.pflash01,property=secure,value=on \
> -drive if=pflash,format=raw,unit=0,readonly=on,file=Build/OvmfIa32/DEBUG_GCC5/FV/OVMF_CODE.fd \
> -drive if=pflash,format=raw,unit=1,snapshot=on,file=Build/OvmfIa32/DEBUG_GCC5/FV/OVMF_VARS.fd \
> -drive id=hdd,if=none,format=qcow2,snapshot=on,file=fedora-30-efi-systemd-i686.qcow2 \
> -device virtio-scsi-pci,id=scsi0 \
> -device scsi-hd,drive=hdd,bus=scsi0.0,bootindex=1
>
> (Once you get a login prompt, feel free to interrupt QEMU with Ctrl-C.)
>
> (3) Test using a 64-bit guest on an Intel host:
>
> $ build -a IA32 -a X64 -b DEBUG -p OvmfPkg/OvmfPkgIa32X64.dsc -t GCC5 -D SMM_REQUIRE
>
> $ qemu-system-x86_64 \
> -cpu host \
> -machine q35,smm=on,accel=kvm \
> -m 4096 \
> -smp 4 \
> -global driver=cfi.pflash01,property=secure,value=on \
> -drive if=pflash,format=raw,unit=0,readonly=on,file=Build/Ovmf3264/DEBUG_GCC5/FV/OVMF_CODE.fd \
> -drive if=pflash,format=raw,unit=1,snapshot=on,file=Build/Ovmf3264/DEBUG_GCC5/FV/OVMF_VARS.fd \
> -drive id=hdd,if=none,format=qcow2,snapshot=on,file=fedora-31-efi-grub2-x86_64.qcow2 \
> -device virtio-scsi-pci,id=scsi0 \
> -device scsi-hd,drive=hdd,bus=scsi0.0,bootindex=1
>
> Tested on real AMD Hardware
>
> UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfileInternal.h | 3 +++
> UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c | 9 ++++++++-
> UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm | 19 +++++++++++++++++--
> UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm | 20 ++++++++++++++++++--
> 4 files changed, 46 insertions(+), 5 deletions(-)
For this patch:
Reviewed-by: Laszlo Ersek <lersek at redhat.com>
However, can you please clarify one bit, with regard to testing:
I understand the regression tests in a 32-bit guest on Intel, and in a
64-bit guests on Intel. I also understand the test on a physical AMD
machine (in other words, you built a physical platform firmware for an
AMD board, flashed it, and tested it.)
However, your notes do not seem to mention test (4) that I requested:
"(4) Test using a 64-bit guest on an AMD host -- just repeat step (3) on
an AMD host."
https://edk2.groups.io/g/devel/message/61344
(alternative link:
<http://mid.mail-archive.com/5f2fd5a9-2107-503a-406b-de08529dcb56@redhat.com>)
That is also important. Test (3) intentionally uses "-cpu host", so the
guest will see a different CPU model when run on an Intel host (3) vs.
on an AMD host (4). I'd like to know that the patched 64-bit SMI entry
code continues working in both guest environments (i.e. when seeing
either an Intel CPU model or an AMD CPU model).
I did not request the same "duality" with test (2) -- as you see, there
I wrote "-cpu coreduo,-nx"; i.e., Intel only. The reason is that "-cpu
coreduo,-nx" is more or less the only 32-bit SMM environment that I
generally know about, and verify -- I simply do not have a 32-bit AMD
CPU model "baseline" to test against. This is why I didn't request "-cpu
host" in (2), and consequently, why I didn't request (2) to be run on
both AMD and Intel hosts.
So... Can you please run test (4) too -- i.e., 64-bit guest on an AMD
host, with "-cpu host"?
Thanks!
Laszlo
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