sev/i386: Allow AP booting under SEV-ES

When SEV-ES is enabled, it is not possible modify the guests register
state after it has been initially created, encrypted and measured.

Normally, an INIT-SIPI-SIPI request is used to boot the AP. However, the
hypervisor cannot emulate this because it cannot update the AP register
state. For the very first boot by an AP, the reset vector CS segment
value and the EIP value must be programmed before the register has been
encrypted and measured. Search the guest firmware for the guest for a
specific GUID that tells Qemu the value of the reset vector to use.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <22db2bfb4d6551aed661a9ae95b4fdbef613ca21.1611682609.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2021-02-08 15:04:52 +01:00
parent 9681f8677f
commit b2f73a0784
6 changed files with 151 additions and 1 deletions

View file

@ -21,4 +21,8 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp);
int sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp);
int sev_inject_launch_secret(const char *hdr, const char *secret,
uint64_t gpa, Error **errp);
int sev_es_save_reset_vector(void *flash_ptr, uint64_t flash_size);
void sev_es_set_reset_vector(CPUState *cpu);
#endif