The current implementation has three bugs,
* segment limits are not enforced in protected mode if the L bit is set
in the target segment descriptor
* segment limits are not enforced in compatibility mode (ljmp to 32-bit
code segment in long mode)
* #GP(new_cs) is generated rather than #GP(0)
Now the segment limits are enforced if we're not in long mode OR the
target code segment doesn't have the L bit set.
Backports commit db7196db5d5d932f388643baae6835f8dcda6921 from qemu
Currently call gates are always treated as 32-bit gates. In IA-32e mode
(either compatibility or 64-bit submode), system segment descriptors are
always 64-bit. Treating them as 32-bit has the expected unfortunate
effect: only the lower 32 bits of the offset are loaded, the stack
pointer is truncated, a bad new stack pointer is loaded from the TSS (if
switching privilege levels), etc.
This change adds support for 64-bit call gate to the lcall and ljmp
instructions. Additionally, there should be a check for non-canonical
stack pointers, but I've omitted that since there doesn't seem to be
checks for non-canonical addresses in this code elsewhere.
I've left the raise_exception_err_ra lines unwapped at 80 columns to
match the style in the rest of the file.
Backports commit 0aca060526d3ff9632aaed66e8611814580c13de from qemu
Check for SVM interception prior to injecting an NMI. Tested via the
Jailhouse hypervisor.
Backports commit 02f7fd25a446a220905c2e5cb0fc3655d7f63b29 from qemu
Move the handling of conforming code segments before the handling
of stack switch.
Because dpl == cpl after the new "if", it's now unnecessary to check
the C bit when testing dpl < cpl. Furthermore, dpl > cpl is checked
slightly above the modified code, so the final "else" is unreachable
and we can remove it.
Backports commit 1110bfe6f5600017258fa6578f9c17ec25b32277 from qemu
In do_interrupt64(), when interrupt stack table(ist) is enabled
and the the target code segment is conforming(e2 & DESC_C_MASK), the
old implementation always set new CPL to 0, and SS.RPL to 0.
This is incorrect for when CPL3 code access a CPL0 conforming code
segment, the CPL should remain unchanged. Otherwise higher privileged
code can be compromised.
The patch fix this for always set dpl = cpl when the target code segment
is conforming, and modify the last parameter `flags`, which contains
correct new CPL, in cpu_x86_load_seg_cache().
Backports commit e95e9b88ba5f4a6c17f4d0c3a3a6bf3f648bb328 from qemu
Paths through the softmmu code during code generation now need to be audited
to check for double locking of tb_lock. In particular, VMEXIT can take tb_lock
through cpu_vmexit -> cpu_x86_update_cr4 -> tlb_flush.
To avoid this, split VMEXIT delivery in two parts, similar to what is done with
exceptions. cpu_vmexit only records the VMEXIT exit code and information, and
cc->do_interrupt can then deliver it when it is safe to take the lock.
Backports commit 10cde894b63146139f981857e4eedf756fa53dcb from qemu
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Backports commit fcf5ef2ab52c621a4617ebbef36bf43b4003f4c0 from qemu
