Commit 106ed2ca authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: SVM: WARN, but continue, if misc_cg_set_capacity() fails 



WARN and continue if misc_cg_set_capacity() fails, as the only scenario
in which it can fail is if the specified resource is invalid, which should
never happen when CONFIG_KVM_AMD_SEV=y.  Deliberately not bailing "fixes"
a theoretical bug where KVM would leak the ASID bitmaps on failure, which
again can't happen.

If the impossible should happen, the end result is effectively the same
with respect to SEV and SEV-ES (they are unusable), while continuing on
has the advantage of letting KVM load, i.e. userspace can still run
non-SEV guests.

Reported-by: default avatarAlexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Link: https://lore.kernel.org/r/20230607004449.1421131-1-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 6d1bc975

arch/x86/kvm/svm/sev.c

+2 −6
Original line number Diff line number Diff line
@@ -2216,9 +2216,7 @@ void __init sev_hardware_setup(void) 
	}



	sev_asid_count = max_sev_asid - min_sev_asid + 1;

	if (misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count))

		goto out;



	WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count));

	sev_supported = true;



	/* SEV-ES support requested? */
@@ -2243,9 +2241,7 @@ void __init sev_hardware_setup(void) 
		goto out;



	sev_es_asid_count = min_sev_asid - 1;

	if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count))

		goto out;



	WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count));

	sev_es_supported = true;



out: