From e0506bcba5992650b1190de9125f5963a30f32e2 Mon Sep 17 00:00:00 2001 From: Izik Eidus Date: Sun, 11 Nov 2007 22:10:22 +0200 Subject: [PATCH] KVM: Change kvm_{read,write}_guest() to use copy_{from,to}_user() This changes kvm_write_guest_page/kvm_read_guest_page to use copy_to_user/read_from_user, as a result we get better speed and better dirty bit tracking. Signed-off-by: Izik Eidus Signed-off-by: Avi Kivity --- drivers/kvm/kvm_main.c | 38 ++++++++++++++------------------------ 1 file changed, 14 insertions(+), 24 deletions(-) diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 04544aecf22f..d68901bd0693 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -630,20 +630,15 @@ static int next_segment(unsigned long len, int offset) int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, int len) { - void *page_virt; - struct page *page; + int r; + unsigned long addr; - page = gfn_to_page(kvm, gfn); - if (is_error_page(page)) { - kvm_release_page(page); + addr = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(addr)) + return -EFAULT; + r = copy_from_user(data, (void __user *)addr + offset, len); + if (r) return -EFAULT; - } - page_virt = kmap_atomic(page, KM_USER0); - - memcpy(data, page_virt + offset, len); - - kunmap_atomic(page_virt, KM_USER0); - kvm_release_page(page); return 0; } EXPORT_SYMBOL_GPL(kvm_read_guest_page); @@ -671,21 +666,16 @@ EXPORT_SYMBOL_GPL(kvm_read_guest); int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, int offset, int len) { - void *page_virt; - struct page *page; + int r; + unsigned long addr; - page = gfn_to_page(kvm, gfn); - if (is_error_page(page)) { - kvm_release_page(page); + addr = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(addr)) + return -EFAULT; + r = copy_to_user((void __user *)addr + offset, data, len); + if (r) return -EFAULT; - } - page_virt = kmap_atomic(page, KM_USER0); - - memcpy(page_virt + offset, data, len); - - kunmap_atomic(page_virt, KM_USER0); mark_page_dirty(kvm, gfn); - kvm_release_page(page); return 0; } EXPORT_SYMBOL_GPL(kvm_write_guest_page); -- 2.30.2