Hi David,
On Thu, 24 Jun 2021 04:57:45 +0100, David Stevens stevensd@chromium.org wrote:
From: David Stevens stevensd@chromium.org
Return a struct kvm_pfn_page containing both a pfn and an optional struct page from the gfn_to_pfn family of functions. This differentiates the gup and follow_fault_pfn cases, which allows callers that only need a pfn to avoid touching the page struct in the latter case. For callers that need a struct page, introduce a helper function that unwraps a struct kvm_pfn_page into a struct page. This helper makes the call to kvm_get_pfn which had previously been in hva_to_pfn_remapped.
For now, wrap all calls to gfn_to_pfn functions in the new helper function. Callers which don't need the page struct will be updated in follow-up patches.
Signed-off-by: David Stevens stevensd@chromium.org
arch/arm64/kvm/mmu.c | 5 +- arch/mips/kvm/mmu.c | 3 +- arch/powerpc/kvm/book3s.c | 3 +- arch/powerpc/kvm/book3s_64_mmu_hv.c | 5 +- arch/powerpc/kvm/book3s_64_mmu_radix.c | 5 +- arch/powerpc/kvm/book3s_hv_uvmem.c | 4 +- arch/powerpc/kvm/e500_mmu_host.c | 2 +- arch/x86/kvm/mmu/mmu.c | 11 ++- arch/x86/kvm/mmu/mmu_audit.c | 2 +- arch/x86/kvm/x86.c | 2 +- drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +- include/linux/kvm_host.h | 27 ++++-- include/linux/kvm_types.h | 5 + virt/kvm/kvm_main.c | 121 +++++++++++++------------ 14 files changed, 109 insertions(+), 88 deletions(-)
[...]
+kvm_pfn_t kvm_pfn_page_unwrap(struct kvm_pfn_page pfnpg) +{
- if (pfnpg.page)
return pfnpg.pfn;- kvm_get_pfn(pfnpg.pfn);
- return pfnpg.pfn;
+} +EXPORT_SYMBOL_GPL(kvm_pfn_page_unwrap);
I'd really like to see a tiny bit of documentation explaining that calls to kvm_pfn_page_unwrap() are not idempotent.
Otherwise, looks good to me.
Thanks,
M.