On 21/10/21 00:01, Jim Mattson wrote:
On Wed, Oct 20, 2021 at 2:31 PM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
On 20/10/21 23:18, Jim Mattson wrote:
- vmcs_write(GUEST_LIMIT_TR, tss_descr.limit);
+ vmcs_write(GUEST_LIMIT_TR, 0x67);
Isn't the limit still set to 0xFFFF in {cstart,cstart64}.S? And
doesn't the VMware backdoor test assume there's room for an I/O
permission bitmap?
Yes, but this is just for L2. The host TR limit is restored to 0x67 on
every vmexit, and it seemed weird to run L1 and L2 with different limits.
Perhaps you could change the limits in the GDT entries to match?
So keep it 0x67 and adjust it to the size of the IOPM in the VMware
backdoor test?
Right. That would seem to achieve the greatest consistency.
Let's just add a get_gdt_entry_limit that takes into account the G bit too.
Paolo
