qemu/target
Paolo Bonzini 798d8ec0da target/i386: do not consult nonexistent host leaves
When cache_info_passthrough is requested, QEMU passes the host values
of the cache information CPUID leaves down to the guest.  However,
it blindly assumes that the CPUID leaf exists on the host, and this
cannot be guaranteed: for example, KVM has recently started to
synthesize AMD leaves up to 0x80000021 in order to provide accurate
CPU bug information to guests.

Querying a nonexistent host leaf fills the output arguments of
host_cpuid with data that (albeit deterministic) is nonsensical
as cache information, namely the data in the highest Intel CPUID
leaf.  If said highest leaf is not ECX-dependent, this can even
cause an infinite loop when kvm_arch_init_vcpu prepares the input
to KVM_SET_CPUID2.  The infinite loop is only terminated by an
abort() when the array gets full.

Reported-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-12 12:07:05 +02:00
..
alpha Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
arm Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
avr Clean up decorations and whitespace around header guards 2022-05-11 16:50:32 +02:00
cris Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
hexagon Clean up decorations and whitespace around header guards 2022-05-11 16:50:32 +02:00
hppa Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
i386 target/i386: do not consult nonexistent host leaves 2022-05-12 12:07:05 +02:00
m68k Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
microblaze Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
mips Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
nios2 Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
openrisc Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
ppc Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
riscv Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
rx Fix usp/isp swapping upon clrpsw/setpsw. 2022-04-21 16:45:41 -07:00
s390x Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
sh4 Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
sparc Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
tricore Normalize header guard symbol definition 2022-05-11 16:50:26 +02:00
xtensa Clean up decorations and whitespace around header guards 2022-05-11 16:50:32 +02:00
Kconfig meson: Introduce target-specific Kconfig 2021-07-09 18:21:34 +02:00
meson.build Drop the deprecated unicore32 target 2021-05-12 18:20:52 +02:00