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authorSean Christopherson <seanjc@google.com>2021-12-06 22:54:11 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2021-12-08 12:24:20 +0300
commit537a17b3149300987456e8949ccb991e604047d6 (patch)
treed87ce72b874aeb22587887b149d072c5d733703d /virt/kvm
parentce5f0215620c11a5829da7f30bebf3adeeef3345 (diff)
downloadlinux-537a17b3149300987456e8949ccb991e604047d6.tar.xz
KVM: Let/force architectures to deal with arch specific memslot data
Pass the "old" slot to kvm_arch_prepare_memory_region() and force arch code to handle propagating arch specific data from "new" to "old" when necessary. This is a baby step towards dynamically allocating "new" from the get go, and is a (very) minor performance boost on x86 due to not unnecessarily copying arch data. For PPC HV, copy the rmap in the !CREATE and !DELETE paths, i.e. for MOVE and FLAGS_ONLY. This is functionally a nop as the previous behavior would overwrite the pointer for CREATE, and eventually discard/ignore it for DELETE. For x86, copy the arch data only for FLAGS_ONLY changes. Unlike PPC HV, x86 needs to reallocate arch data in the MOVE case as the size of x86's allocations depend on the alignment of the memslot's gfn. Opportunistically tweak kvm_arch_prepare_memory_region()'s param order to match the "commit" prototype. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> [mss: add missing RISCV kvm_arch_prepare_memory_region() change] Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <67dea5f11bbcfd71e3da5986f11e87f5dd4013f9.1638817639.git.maciej.szmigiero@oracle.com>
Diffstat (limited to 'virt/kvm')
-rw-r--r--virt/kvm/kvm_main.c5
1 files changed, 1 insertions, 4 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a7a1c872fe6d..46060cc542ef 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1636,10 +1636,7 @@ static int kvm_set_memslot(struct kvm *kvm,
old.as_id = new->as_id;
}
- /* Copy the arch-specific data, again after (re)acquiring slots_arch_lock. */
- memcpy(&new->arch, &old.arch, sizeof(old.arch));
-
- r = kvm_arch_prepare_memory_region(kvm, new, mem, change);
+ r = kvm_arch_prepare_memory_region(kvm, mem, &old, new, change);
if (r)
goto out_slots;