KVM: x86/mmu: Allow enabling/disabling dirty logging under MMU read lock

mainline inclusion
from mainline-v5.13-rc1
commit 24ae4cfa
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I7S3VQ
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=24ae4cfaaaa22a4f293acd0c7d97804454b7e9fb



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To reduce lock contention and interference with page fault handlers,
allow the TDP MMU functions which enable and disable dirty logging
to operate under the MMU read lock.

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210401233736.638171-12-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

conflict:
	arch/x86/kvm/mmu/tdp_mmu.c
	arch/x86/kvm/mmu/mmu.c

Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com>