On 12/25/23 07:49, Michael Tokarev wrote:
12.12.2023 20:25, Richard Henderson:
In 32-bit mode, pc = eip + cs_base is also 32-bit, and must wrap.
Failure to do so results in incorrect memory exceptions to the guest.
Before 732d548732ed, this was implicitly done via truncation to
target_ulong but only in qemu-system-i386, not qemu-system-x86_64.
To fix this, we must add conditional zero-extensions.
Since we have to test for 32 vs 64-bit anyway, note that cs_base
is always zero in 64-bit mode.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2022
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
This may be too late for 8.2; if not, then 8.2.1 and 8.1.next.
I think I have found all forms of pc <-> eip, but another set
of eyes would be appreciated.
This change breaks trivial 4M edk2 boot - both in 8.2.0 and in
8.1.4 (which also has this commit now).
qemu-system-x86_64 -machine q35 -no-user-config -nodefaults -display none \
-serial stdio \
-drive
file=/usr/share/OVMF/OVMF_CODE_4M.secboot.fd,if=pflash,format=raw,readonly=on \
-drive
file=/usr/share/OVMF/OVMF_VARS_4M.ms.fd,if=pflash,format=raw,snapshot=on
After this change, nothing is printed on the serial console anymore
(or in vga, whatever). Before that commit, usual edk2 boot sequence
is seen.
Nothing has changed with the 2M variant though.
Ack. Looking at it....
r~
