KVM: x86: Disallow KVM_CAP_X86_DISABLE_EXITS after vCPU creation

Reject KVM_CAP_X86_DISABLE_EXITS if vCPUs have been created, as disabling
PAUSE/MWAIT/HLT exits after vCPUs have been created is broken and useless,
e.g. except for PAUSE on SVM, the relevant intercepts aren't updated after
vCPU creation.  vCPUs may also end up with an inconsistent configuration
if exits are disabled between creation of multiple vCPUs.

Cc: Hou Wenlong <houwenlong.hwl@antgroup.com>
Link: https://lore.kernel.org/all/9227068821b275ac547eb2ede09ec65d2281fe07.1680179693.git.houwenlong.hwl@antgroup.com
Link: https://lore.kernel.org/all/20230121020738.2973-2-kechenl@nvidia.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-14-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson
2024-11-27 17:33:40 -08:00
parent 21d7f06d1a
commit 04cd8f8628
2 changed files with 7 additions and 0 deletions

View File

@@ -7670,6 +7670,7 @@ branch to guests' 0x200 interrupt vector.
:Architectures: x86
:Parameters: args[0] defines which exits are disabled
:Returns: 0 on success, -EINVAL when args[0] contains invalid exits
or if any vCPUs have already been created
Valid bits in args[0] are::