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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 <ieidus@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Izik Eidus 2008-12-29 01:42:20 +02:00 committed by Avi Kivity
parent 77c2002e7c
commit 0f34607440
2 changed files with 14 additions and 51 deletions
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62
arch/x86/kvm/x86.c
View File

@ -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)

3
include/linux/kvm_types.h
View File

@ -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;