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| author | Paul Mackerras <paulus@ozlabs.org> | 2018-12-12 07:17:17 +0300 |
|---|---|---|
| committer | Paul Mackerras <paulus@ozlabs.org> | 2018-12-17 02:58:51 +0300 |
| commit | 5af3e9d06d830d52864b39c86724dc39b463eddd (patch) | |
| tree | e8287e8a6eb9ec85a606ef1b1917d15a42a91c11 /arch/powerpc/kvm/book3s_64_mmu_radix.c | |
| parent | c43c3a8683fe624b67b91a06f1c25cd752a05b3b (diff) | |
| download | linux-5af3e9d06d830d52864b39c86724dc39b463eddd.tar.xz | |
KVM: PPC: Book3S HV: Flush guest mappings when turning dirty tracking on/off
This adds code to flush the partition-scoped page tables for a radix
guest when dirty tracking is turned on or off for a memslot. Only the
guest real addresses covered by the memslot are flushed. The reason
for this is to get rid of any 2M PTEs in the partition-scoped page
tables that correspond to host transparent huge pages, so that page
dirtiness is tracked at a system page (4k or 64k) granularity rather
than a 2M granularity. The page tables are also flushed when turning
dirty tracking off so that the memslot's address space can be
repopulated with THPs if possible.
To do this, we add a new function kvmppc_radix_flush_memslot(). Since
this does what's needed for kvmppc_core_flush_memslot_hv() on a radix
guest, we now make kvmppc_core_flush_memslot_hv() call the new
kvmppc_radix_flush_memslot() rather than calling kvm_unmap_radix()
for each page in the memslot. This has the effect of fixing a bug in
that kvmppc_core_flush_memslot_hv() was previously calling
kvm_unmap_radix() without holding the kvm->mmu_lock spinlock, which
is required to be held.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc/kvm/book3s_64_mmu_radix.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_radix.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index 52711eb052f5..d675ad92c7ad 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -958,6 +958,26 @@ long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm, return 0; } +void kvmppc_radix_flush_memslot(struct kvm *kvm, + const struct kvm_memory_slot *memslot) +{ + unsigned long n; + pte_t *ptep; + unsigned long gpa; + unsigned int shift; + + gpa = memslot->base_gfn << PAGE_SHIFT; + spin_lock(&kvm->mmu_lock); + for (n = memslot->npages; n; --n) { + ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift); + if (ptep && pte_present(*ptep)) + kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot, + kvm->arch.lpid); + gpa += PAGE_SIZE; + } + spin_unlock(&kvm->mmu_lock); +} + static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info, int psize, int *indexp) { |