KVM: VMX: Don't use highmem pages for the msr and pio bitmaps

Highmem pages are a pain, and saving three lowmem pages on i386 isn't worth
the extra code.

Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index bb48133..b20c9e4 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -111,9 +111,9 @@ static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
 static DEFINE_PER_CPU(struct list_head, vcpus_on_cpu);
 
-static struct page *vmx_io_bitmap_a;
-static struct page *vmx_io_bitmap_b;
-static struct page *vmx_msr_bitmap;
+static unsigned long *vmx_io_bitmap_a;
+static unsigned long *vmx_io_bitmap_b;
+static unsigned long *vmx_msr_bitmap;
 
 static DECLARE_BITMAP(vmx_vpid_bitmap, VMX_NR_VPIDS);
 static DEFINE_SPINLOCK(vmx_vpid_lock);
@@ -2082,9 +2082,9 @@ static void allocate_vpid(struct vcpu_vmx *vmx)
        spin_unlock(&vmx_vpid_lock);
 }
 
-static void vmx_disable_intercept_for_msr(struct page *msr_bitmap, u32 msr)
+static void vmx_disable_intercept_for_msr(unsigned long *msr_bitmap, u32 msr)
 {
-       void *va;
+       int f = sizeof(unsigned long);
 
        if (!cpu_has_vmx_msr_bitmap())
                return;
@@ -2094,16 +2094,14 @@ static void vmx_disable_intercept_for_msr(struct page *msr_bitmap, u32 msr)
         * have the write-low and read-high bitmap offsets the wrong way round.
         * We can control MSRs 0x00000000-0x00001fff and 0xc0000000-0xc0001fff.
         */
-       va = kmap(msr_bitmap);
        if (msr <= 0x1fff) {
-               __clear_bit(msr, va + 0x000); /* read-low */
-               __clear_bit(msr, va + 0x800); /* write-low */
+               __clear_bit(msr, msr_bitmap + 0x000 / f); /* read-low */
+               __clear_bit(msr, msr_bitmap + 0x800 / f); /* write-low */
        } else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
                msr &= 0x1fff;
-               __clear_bit(msr, va + 0x400); /* read-high */
-               __clear_bit(msr, va + 0xc00); /* write-high */
+               __clear_bit(msr, msr_bitmap + 0x400 / f); /* read-high */
+               __clear_bit(msr, msr_bitmap + 0xc00 / f); /* write-high */
        }
-       kunmap(msr_bitmap);
 }
 
 /*
@@ -2121,11 +2119,11 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
        u32 exec_control;
 
        /* I/O */
-       vmcs_write64(IO_BITMAP_A, page_to_phys(vmx_io_bitmap_a));
-       vmcs_write64(IO_BITMAP_B, page_to_phys(vmx_io_bitmap_b));
+       vmcs_write64(IO_BITMAP_A, __pa(vmx_io_bitmap_a));
+       vmcs_write64(IO_BITMAP_B, __pa(vmx_io_bitmap_b));
 
        if (cpu_has_vmx_msr_bitmap())
-               vmcs_write64(MSR_BITMAP, page_to_phys(vmx_msr_bitmap));
+               vmcs_write64(MSR_BITMAP, __pa(vmx_msr_bitmap));
 
        vmcs_write64(VMCS_LINK_POINTER, -1ull); /* 22.3.1.5 */
 
@@ -3695,20 +3693,19 @@ static struct kvm_x86_ops vmx_x86_ops = {
 
 static int __init vmx_init(void)
 {
-       void *va;
        int r;
 
-       vmx_io_bitmap_a = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+       vmx_io_bitmap_a = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_io_bitmap_a)
                return -ENOMEM;
 
-       vmx_io_bitmap_b = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+       vmx_io_bitmap_b = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_io_bitmap_b) {
                r = -ENOMEM;
                goto out;
        }
 
-       vmx_msr_bitmap = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+       vmx_msr_bitmap = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_msr_bitmap) {
                r = -ENOMEM;
                goto out1;
@@ -3718,18 +3715,12 @@ static int __init vmx_init(void)
         * Allow direct access to the PC debug port (it is often used for I/O
         * delays, but the vmexits simply slow things down).
         */
-       va = kmap(vmx_io_bitmap_a);
-       memset(va, 0xff, PAGE_SIZE);
-       clear_bit(0x80, va);
-       kunmap(vmx_io_bitmap_a);
+       memset(vmx_io_bitmap_a, 0xff, PAGE_SIZE);
+       clear_bit(0x80, vmx_io_bitmap_a);
 
-       va = kmap(vmx_io_bitmap_b);
-       memset(va, 0xff, PAGE_SIZE);
-       kunmap(vmx_io_bitmap_b);
+       memset(vmx_io_bitmap_b, 0xff, PAGE_SIZE);
 
-       va = kmap(vmx_msr_bitmap);
-       memset(va, 0xff, PAGE_SIZE);
-       kunmap(vmx_msr_bitmap);
+       memset(vmx_msr_bitmap, 0xff, PAGE_SIZE);
 
        set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */
 
@@ -3762,19 +3753,19 @@ static int __init vmx_init(void)
        return 0;
 
 out2:
-       __free_page(vmx_msr_bitmap);
+       free_page((unsigned long)vmx_msr_bitmap);
 out1:
-       __free_page(vmx_io_bitmap_b);
+       free_page((unsigned long)vmx_io_bitmap_b);
 out:
-       __free_page(vmx_io_bitmap_a);
+       free_page((unsigned long)vmx_io_bitmap_a);
        return r;
 }
 
 static void __exit vmx_exit(void)
 {
-       __free_page(vmx_msr_bitmap);
-       __free_page(vmx_io_bitmap_b);
-       __free_page(vmx_io_bitmap_a);
+       free_page((unsigned long)vmx_msr_bitmap);
+       free_page((unsigned long)vmx_io_bitmap_b);
+       free_page((unsigned long)vmx_io_bitmap_a);
 
        kvm_exit();
 }