From: Xiaoyao Li <xiaoyao...@intel.com> Kirill Martynov reported assertation in cpu_asidx_from_attrs() being hit when x86_cpu_dump_state() is called to dump the CPU state[*]. It happens when the CPU is in SMM and KVM emulation failure due to misbehaving guest.
The root cause is that QEMU i386 never enables the SMM address space for cpu since KVM SMM support has been added. Enable the SMM cpu address space under KVM when the SMM is enabled for the x86machine. [*] https://lore.kernel.org/qemu-devel/20250523154431.506993-1-stdcalll...@yandex-team.ru/ Reported-by: Kirill Martynov <stdcalll...@yandex-team.ru> Reviewed-by: Zhao Liu <zhao1....@intel.com> Tested-by: Kirill Martynov <stdcalll...@yandex-team.ru> Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com> Link: https://lore.kernel.org/r/20250730095253.1833411-2-xiaoyao...@intel.com Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> (cherry picked from commit 0516f4b70264b9710a25718d21bd35ef463c875e) Signed-off-by: Michael Tokarev <m...@tls.msk.ru> diff --git a/system/physmem.c b/system/physmem.c index 32f5895b80..82d453ddde 100644 --- a/system/physmem.c +++ b/system/physmem.c @@ -763,9 +763,6 @@ void cpu_address_space_init(CPUState *cpu, int asidx, cpu->as = as; } - /* KVM cannot currently support multiple address spaces. */ - assert(asidx == 0 || !kvm_enabled()); - if (!cpu->cpu_ases) { cpu->cpu_ases = g_new0(CPUAddressSpace, cpu->num_ases); cpu->cpu_ases_count = cpu->num_ases; @@ -788,8 +785,6 @@ void cpu_address_space_destroy(CPUState *cpu, int asidx) assert(cpu->cpu_ases); assert(asidx >= 0 && asidx < cpu->num_ases); - /* KVM cannot currently support multiple address spaces. */ - assert(asidx == 0 || !kvm_enabled()); cpuas = &cpu->cpu_ases[asidx]; if (tcg_enabled()) { diff --git a/target/i386/kvm/kvm-cpu.c b/target/i386/kvm/kvm-cpu.c index 6269fa8045..80ae347508 100644 --- a/target/i386/kvm/kvm-cpu.c +++ b/target/i386/kvm/kvm-cpu.c @@ -13,6 +13,7 @@ #include "qapi/error.h" #include "system/system.h" #include "hw/boards.h" +#include "hw/i386/x86.h" #include "kvm_i386.h" #include "accel/accel-cpu-target.h" @@ -90,6 +91,15 @@ static bool kvm_cpu_realizefn(CPUState *cs, Error **errp) kvm_set_guest_phys_bits(cs); } + /* + * When SMM is enabled, there is 2 address spaces. Otherwise only 1. + * + * Only initialize address space 0 here, the second one for SMM is + * initialized at register_smram_listener() after machine init done. + */ + cs->num_ases = x86_machine_is_smm_enabled(X86_MACHINE(current_machine)) ? 2 : 1; + cpu_address_space_init(cs, 0, "cpu-memory", cs->memory); + return true; } diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 141694f803..589f879beb 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -2678,6 +2678,7 @@ static MemoryRegion smram_as_mem; static void register_smram_listener(Notifier *n, void *unused) { + CPUState *cpu; MemoryRegion *smram = (MemoryRegion *) object_resolve_path("/machine/smram", NULL); @@ -2702,6 +2703,10 @@ static void register_smram_listener(Notifier *n, void *unused) address_space_init(&smram_address_space, &smram_as_root, "KVM-SMRAM"); kvm_memory_listener_register(kvm_state, &smram_listener, &smram_address_space, 1, "kvm-smram"); + + CPU_FOREACH(cpu) { + cpu_address_space_init(cpu, 1, "cpu-smm", &smram_as_root); + } } static void *kvm_msr_energy_thread(void *data) -- 2.47.3
