On 1/14/21 11:12 AM, Sean Christopherson wrote:
On Thu, Jan 14, 2021, Tom Lendacky wrote:
On 1/13/21 6:36 PM, Sean Christopherson wrote:
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")
Oops, missed this last time... I don't think the Fixes: tag is needed
anymore unless you don't want the memory consumption of the first bitmap,
should the allocation of the second bitmap fail, until kvm_amd is
rmmod'ed. Up to you.
Thanks,
Tom
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index c8ffdbc81709..0eeb6e1b803d 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1274,8 +1274,10 @@ 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);
Until that future change, you probably need to do sev_asid_bitmap = NULL
here to avoid an issue in sev_hardware_teardown() when it tries to free it
again.
Argh, you're right. Thanks!
