On 8/6/25 09:58, Zero Tang wrote:
Replaces "long" with "int64_t" during canonicalization.
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In Linux GCC, "long" has 8 bytes. However, in msys2 GCC, "long" has 4
bytes. In this case, canonicalization would set all high bits to 1 when
the segment base is bigger than 0x7FFF (assuming 48-bit linear address).
This is why QEMU-TCG in Windows cannot boot a bluepill-like hypervisor
in UEFI, in that the guest IDT and GDT bases are above 0x7FFF, thereby
resulting in incorrect bases. When an interrupt arrives, it would
trigger a #PF exception; the #PF would trigger again, resulting in a #DF
exception; the #PF would trigger for the third time, resulting in
triple-fault, and eventually causes the shutdown VM-Exit to the
bluepill hypervisor right after it boots.
In summary, this patch replaces "long" with "int64_t" in order to enforce
the canonicalization with 64-bit signed integers.
Signed-off-by: Zero Tang <zero.tang...@gmail.com>
Queued, thanks. However, please note that the patch is not formatted
correctly; do not send patches as HTML mail. In this case it was one
line of code only so I fixed it up.
Paolo
