diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2025-05-29 16:18:00 -0500 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-06-20 13:33:45 -0700 |
| commit | 24be2b7956a545945fcb560d42e3ea86406dba09 (patch) | |
| tree | 8513900f6de986f21d60d1cb015af2b36260e8c8 | |
| parent | 9f4701e05faeec20350d9fc550e37ae8d2e08c88 (diff) | |
KVM: SVM: Allow SNP guest policy to specify SINGLE_SOCKET
KVM currently returns -EINVAL when it attempts to create an SNP guest if
the SINGLE_SOCKET guest policy bit is set. The reason for this action is
that KVM would need specific support (SNP_ACTIVATE_EX command support) to
achieve this when running on a system with more than one socket. However,
the SEV firmware will make the proper check and return POLICY_FAILURE
during SNP_ACTIVATE if the single socket guest policy bit is set and the
system has more than one socket:
- System with one socket
- Guest policy SINGLE_SOCKET == 0 ==> SNP_ACTIVATE succeeds
- Guest policy SINGLE_SOCKET == 1 ==> SNP_ACTIVATE succeeds
- System with more than one socket
- Guest policy SINGLE_SOCKET == 0 ==> SNP_ACTIVATE succeeds
- Guest policy SINGLE_SOCKET == 1 ==> SNP_ACTIVATE fails with
POLICY_FAILURE
Remove the check for the SINGLE_SOCKET policy bit from snp_launch_start()
and allow the firmware to perform the proper checking.
This does have the effect of allowing an SNP guest with the SINGLE_SOCKET
policy bit set to run on a single socket system, but fail when run on a
system with more than one socket. However, this should not affect existing
SNP guests as setting the SINGLE_SOCKET policy bit is not allowed today.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/4c51018dd3e4f2c543935134d2c4f47076f109f6.1748553480.git.thomas.lendacky@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 9a6dd285dfff..b6a852894dff 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2134,9 +2134,6 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) if (!(params.policy & SNP_POLICY_MASK_RSVD_MBO)) return -EINVAL; - if (params.policy & SNP_POLICY_MASK_SINGLE_SOCKET) - return -EINVAL; - sev->policy = params.policy; sev->snp_context = snp_context_create(kvm, argp); |