Messages in this thread Patch in this message | | | From | John Hubbard <> | Subject | [PATCH 2/2] KVM: SVM: convert get_user_pages() --> pin_user_pages() | Date | Mon, 25 May 2020 23:22:07 -0700 |
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This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls.
There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages.
[1] Documentation/core-api/pin_user_pages.rst
[2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/
Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Signed-off-by: John Hubbard <jhubbard@nvidia.com> --- arch/x86/kvm/svm/sev.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 9693db1af57c..a83f2e73bcbb 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -349,7 +349,7 @@ static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr, return NULL; /* Pin the user virtual address. */ - npinned = get_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages); + npinned = pin_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages); if (npinned != npages) { pr_err("SEV: Failure locking %lu pages.\n", npages); goto err; @@ -362,7 +362,7 @@ static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr, err: if (npinned > 0) - release_pages(pages, npinned); + unpin_user_pages(pages, npinned); kvfree(pages); return NULL; @@ -373,7 +373,7 @@ static void sev_unpin_memory(struct kvm *kvm, struct page **pages, { struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; - release_pages(pages, npages); + unpin_user_pages(pages, npages); kvfree(pages); sev->pages_locked -= npages; } -- 2.26.2
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