From 0f346074403bc109f9569f14b45cb09e83729032 Mon Sep 17 00:00:00 2001 From: Izik Eidus Date: Mon, 29 Dec 2008 01:42:20 +0200 Subject: [PATCH] KVM: remove the vmap usage vmap() on guest pages hides those pages from the Linux mm for an extended (userspace determined) amount of time. Get rid of it. Signed-off-by: Izik Eidus Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 62 ++++++++------------------------------- include/linux/kvm_types.h | 3 +- 2 files changed, 14 insertions(+), 51 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 67f91764e99..2a4f3a69734 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2371,40 +2371,19 @@ int emulate_instruction(struct kvm_vcpu *vcpu, } EXPORT_SYMBOL_GPL(emulate_instruction); -static void free_pio_guest_pages(struct kvm_vcpu *vcpu) -{ - int i; - - for (i = 0; i < ARRAY_SIZE(vcpu->arch.pio.guest_pages); ++i) - if (vcpu->arch.pio.guest_pages[i]) { - kvm_release_page_dirty(vcpu->arch.pio.guest_pages[i]); - vcpu->arch.pio.guest_pages[i] = NULL; - } -} - static int pio_copy_data(struct kvm_vcpu *vcpu) { void *p = vcpu->arch.pio_data; - void *q; + gva_t q = vcpu->arch.pio.guest_gva; unsigned bytes; - int nr_pages = vcpu->arch.pio.guest_pages[1] ? 2 : 1; + int ret; - q = vmap(vcpu->arch.pio.guest_pages, nr_pages, VM_READ|VM_WRITE, - PAGE_KERNEL); - if (!q) { - free_pio_guest_pages(vcpu); - return -ENOMEM; - } - q += vcpu->arch.pio.guest_page_offset; bytes = vcpu->arch.pio.size * vcpu->arch.pio.cur_count; if (vcpu->arch.pio.in) - memcpy(q, p, bytes); + ret = kvm_write_guest_virt(q, p, bytes, vcpu); else - memcpy(p, q, bytes); - q -= vcpu->arch.pio.guest_page_offset; - vunmap(q); - free_pio_guest_pages(vcpu); - return 0; + ret = kvm_read_guest_virt(q, p, bytes, vcpu); + return ret; } int complete_pio(struct kvm_vcpu *vcpu) @@ -2515,7 +2494,6 @@ int kvm_emulate_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, vcpu->arch.pio.in = in; vcpu->arch.pio.string = 0; vcpu->arch.pio.down = 0; - vcpu->arch.pio.guest_page_offset = 0; vcpu->arch.pio.rep = 0; if (vcpu->run->io.direction == KVM_EXIT_IO_IN) @@ -2543,9 +2521,7 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, gva_t address, int rep, unsigned port) { unsigned now, in_page; - int i, ret = 0; - int nr_pages = 1; - struct page *page; + int ret = 0; struct kvm_io_device *pio_dev; vcpu->run->exit_reason = KVM_EXIT_IO; @@ -2557,7 +2533,6 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, vcpu->arch.pio.in = in; vcpu->arch.pio.string = 1; vcpu->arch.pio.down = down; - vcpu->arch.pio.guest_page_offset = offset_in_page(address); vcpu->arch.pio.rep = rep; if (vcpu->run->io.direction == KVM_EXIT_IO_IN) @@ -2577,15 +2552,8 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, else in_page = offset_in_page(address) + size; now = min(count, (unsigned long)in_page / size); - if (!now) { - /* - * String I/O straddles page boundary. Pin two guest pages - * so that we satisfy atomicity constraints. Do just one - * transaction to avoid complexity. - */ - nr_pages = 2; + if (!now) now = 1; - } if (down) { /* * String I/O in reverse. Yuck. Kill the guest, fix later. @@ -2600,15 +2568,7 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, if (vcpu->arch.pio.cur_count == vcpu->arch.pio.count) kvm_x86_ops->skip_emulated_instruction(vcpu); - for (i = 0; i < nr_pages; ++i) { - page = gva_to_page(vcpu, address + i * PAGE_SIZE); - vcpu->arch.pio.guest_pages[i] = page; - if (!page) { - kvm_inject_gp(vcpu, 0); - free_pio_guest_pages(vcpu); - return 1; - } - } + vcpu->arch.pio.guest_gva = address; pio_dev = vcpu_find_pio_dev(vcpu, port, vcpu->arch.pio.cur_count, @@ -2616,7 +2576,11 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, if (!vcpu->arch.pio.in) { /* string PIO write */ ret = pio_copy_data(vcpu); - if (ret >= 0 && pio_dev) { + if (ret == X86EMUL_PROPAGATE_FAULT) { + kvm_inject_gp(vcpu, 0); + return 1; + } + if (ret == 0 && pio_dev) { pio_string_write(pio_dev, vcpu); complete_pio(vcpu); if (vcpu->arch.pio.count == 0) diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h index 9b6f395c962..5f4a18cae26 100644 --- a/include/linux/kvm_types.h +++ b/include/linux/kvm_types.h @@ -43,8 +43,7 @@ typedef hfn_t pfn_t; struct kvm_pio_request { unsigned long count; int cur_count; - struct page *guest_pages[2]; - unsigned guest_page_offset; + gva_t guest_gva; int in; int port; int size; -- 2.41.1