KVM: arm64: Invalidate the table entries upon a range
authorRaghavendra Rao Ananta <rananta@google.com>
Fri, 11 Aug 2023 04:51:26 +0000 (04:51 +0000)
committerMarc Zyngier <maz@kernel.org>
Thu, 17 Aug 2023 08:40:35 +0000 (09:40 +0100)
commitdefc8cc7abf0fcee8d73e440ee02827348d060e0
tree9092158864af8a9452a777891371e959ff1fa6cd
parent3756b6f2bb3a242fef0867b39a23607f5aeca138
KVM: arm64: Invalidate the table entries upon a range

Currently, during the operations such as a hugepage collapse,
KVM would flush the entire VM's context using 'vmalls12e1is'
TLBI operation. Specifically, if the VM is faulting on many
hugepages (say after dirty-logging), it creates a performance
penalty for the guest whose pages have already been faulted
earlier as they would have to refill their TLBs again.

Instead, leverage kvm_tlb_flush_vmid_range() for table entries.
If the system supports it, only the required range will be
flushed. Else, it'll fallback to the previous mechanism.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230811045127.3308641-14-rananta@google.com
arch/arm64/kvm/hyp/pgtable.c