[PATCH v5 02/15] KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails

Sean Christopherson
2021-04-22T02:11:38Z

Free sev_asid_bitmap if the reclaim bitmap allocation fails, othwerise
KVM will unnecessarily keep the bitmap when SEV is not fully enabled.

Freeing the page is also necessary to avoid introducing a bug when a
future patch eliminates svm_sev_enabled() in favor of using the global
'sev' flag directly. While sev_hardware_enabled() checks max_sev_asid,
which is true even if KVM setup fails, 'sev' will be true if and only
if KVM setup fully succeeds.

Fixes: 33af3a7ef9e6 ("KVM: SVM: Reduce WBINVD/DF_FLUSH invocations")
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/sev.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index b4e471b0a231..5ff8a202cc01 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1788,8 +1788,11 @@ void __init sev_hardware_setup(void)
goto out;

sev_reclaim_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
- if (!sev_reclaim_asid_bitmap)
+ if (!sev_reclaim_asid_bitmap) {
+ bitmap_free(sev_asid_bitmap);
+ sev_asid_bitmap = NULL;
goto out;
+ }

pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1);
sev_supported = true;