[PATCH 0/2] KVM: x86: Enhance vendor module error messages

[Sean Christopherson]

Paul Menzel encountered the bad userspace behavior of spamming KVM module
loading on all CPUs, which was mitigated by commit ef935c25fd64 ("kvm: x86:
Limit the number of "kvm: disabled by bios" messages"), except this time
userspace is extra "clever" and spams both kvm_intel and kvm_amd.  Because
the "already loaded the other module" message isn't ratelimited, the bogus
module load managed to spam the kernel log.

Patch 1 addresses another suggestion from Paul by incorporating the vendor
module name into the error messages.

Patch 2 addresses the original report by prioritizing the hardware/bios
support messages over the "already loaded" error.  In additional to
reducing spam, doing so also ensures consistent messaging if a vendor
module isn't supported regardless of what other modules may be loaded.

[*] https://lkml.kernel.org/r/20210818114956.7171-1-pmenzel@xxxxxxxxxxxxx

Sean Christopherson (2):
  KVM: x86: Add vendor name to kvm_x86_ops, use it for error messages
  KVM: x86: Defer "already loaded" check until after basic support
    checks

 arch/x86/include/asm/kvm_host.h |  2 ++
 arch/x86/kvm/svm/svm.c          |  2 ++
 arch/x86/kvm/vmx/vmx.c          |  2 ++
 arch/x86/kvm/x86.c              | 17 +++++++++--------
 4 files changed, 15 insertions(+), 8 deletions(-)

-- 
2.33.0.1079.g6e70778dc9-goog