On 6/2/23 03:15, Sean Christopherson wrote:
Convert VMX's handling of mmu_notifier invalidations of the APIC-access page
from invalidate_range() to KVM's standard invalidate_range_{start,end}().
KVM (ab)uses invalidate_range() to fudge around not stalling vCPUs until
relevant in-flight invalidations complete. Abusing invalidate_range() works,
but it requires one-off code in KVM, sets a bad precedent in KVM, and is
blocking improvements to mmu_notifier's definition of invalidate_range()
due to KVM's usage diverging wildly from the original intent of notifying
IOMMUs of changes to shared page tables.
Clean up the mess by hooking x86's implementation of kvm_unmap_gfn_range()
and stalling vCPUs by re-requesting KVM_REQ_APIC_PAGE_RELOAD until the
invalidation completes.
Sean Christopherson (3):
KVM: VMX: Retry APIC-access page reload if invalidation is in-progress
KVM: x86: Use standard mmu_notifier invalidate hooks for APIC access
page
KVM: x86/mmu: Trigger APIC-access page reload iff vendor code cares
arch/x86/kvm/mmu/mmu.c | 4 ++++
arch/x86/kvm/vmx/vmx.c | 50 ++++++++++++++++++++++++++++++++++++----
arch/x86/kvm/x86.c | 14 -----------
include/linux/kvm_host.h | 3 ---
virt/kvm/kvm_main.c | 18 ---------------
5 files changed, 49 insertions(+), 40 deletions(-)
base-commit: 39428f6ea9eace95011681628717062ff7f5eb5f
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Paolo
