On Fri, May 23, 2025 at 03:44:31PM +0000, Kirill Martynov wrote: > Date: Fri, 23 May 2025 15:44:31 +0000 > From: Kirill Martynov <stdcalll...@yandex-team.ru> > Subject: [PATCH] x86/cpu: Handle SMM mode in x86_cpu_dump_state for softmmu > X-Mailer: git-send-email 2.43.0 > > Certain error conditions can trigger x86_cpu_dump_state() to output CPU state > debug information e.g. KVM emulation failure due to misbehaving guest. > However, if the CPU is in System Management Mode (SMM) when the assertion > in cpu_asidx_from_attrs failure happens because: > > 1. In SMM mode (smm=1), the CPU must use multiple address spaces > with a dedicated SMM address space > 2. On machine types with softmmu, address spaces are hardcoded to 1 > (no multiple address spaces available) > > The assertion occurs in cpu_asidx_from_attrs() when trying to > access memory in SMM mode with insufficient address spaces. > > Fix this by: > 1. If number of address spaces is 1 always use index 0 > 2. In other cases use attr.secure for identified proper index > > This prevents the assertion while still providing useful debug > output during VM shutdown errors. > > Stack trace of the original issue: > #0 ... in raise () from /lib/x86_64-linux-gnu/libc.so.6 > #1 ... in abort () from /lib/x86_64-linux-gnu/libc.so.6 > #2 ... in ?? () from /lib/x86_64-linux-gnu/libc.so.6 > #3 ... in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6 > #4 ... in cpu_asidx_from_attrs (cpu=cpu@entry=0x5578ca2eb340, attrs=...) > at ../hw/core/cpu-sysemu.c:76 > #5 ... in cpu_memory_rw_debug (cpu=cpu@entry=0x5578ca2eb340, > addr=addr@entry=2147258348, ptr=ptr@entry=0x7f5341ca373c, len=len@entry=1, > is_write=is_write@entry=false) at ../softmmu/physmem.c:3529 > #6 ... in x86_cpu_dump_state (cs=0x5578ca2eb340, > f=0x7f53434065c0 <_IO_2_1_stderr_>, flags=<optimized out>) > at ../target/i386/cpu-dump.c:560 > #7 ... in kvm_cpu_exec (cpu=cpu@entry=0x5578ca2eb340) > at ../accel/kvm/kvm-all.c:3000 > #8 ... in kvm_vcpu_thread_fn (arg=arg@entry=0x5578ca2eb340) > at ../accel/kvm/kvm-accel-ops.c:51 > #9 ... in qemu_thread_start (args=<optimized out>) > at ../util/qemu-thread-posix.c:505 > #10 ... in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0 > #11 ... in clone () from /lib/x86_64-linux-gnu/libc.so.6 > > Signed-off-by: Kirill Martynov <stdcalll...@yandex-team.ru> > --- > target/i386/cpu.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-)
Sorry for delay. This fix looks good to me, Reviewed-by: Zhao Liu <zhao1....@intel.com>
