[PATCH][UPDATE] vmx: enable io bitmaps to avoid IO port 0x80 VMEXITs

[PATCH][UPDATE] vmx: enable io bitmaps to avoid IO port 0x80 VMEXITs

[He, Qing]

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This is updated version. Because the bitmaps are only needed to be
mapped at init time, allocating them in high memory if possible saves
low memory and virtual space.

Thanks,
Qing

[-- Attachment #2: kvm-vmx-io-bitmaps-0x80-highmem.patch --]
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diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 1d2b41b..a359f50 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -33,6 +33,9 @@ MODULE_LICENSE("GPL");
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
 
+static struct page *vmx_io_bitmap_a;
+static struct page *vmx_io_bitmap_b;
+
 #ifdef CONFIG_X86_64
 #define HOST_IS_64 1
 #else
@@ -1127,8 +1130,8 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
 	vmcs_write32(GUEST_PENDING_DBG_EXCEPTIONS, 0);
 
 	/* I/O */
-	vmcs_write64(IO_BITMAP_A, 0);
-	vmcs_write64(IO_BITMAP_B, 0);
+	vmcs_write64(IO_BITMAP_A, page_to_phys(vmx_io_bitmap_a));
+	vmcs_write64(IO_BITMAP_B, page_to_phys(vmx_io_bitmap_b));
 
 	guest_write_tsc(0);
 
@@ -1148,7 +1151,7 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
 			       CPU_BASED_HLT_EXITING         /* 20.6.2 */
 			       | CPU_BASED_CR8_LOAD_EXITING    /* 20.6.2 */
 			       | CPU_BASED_CR8_STORE_EXITING   /* 20.6.2 */
-			       | CPU_BASED_UNCOND_IO_EXITING   /* 20.6.2 */
+			       | CPU_BASED_ACTIVATE_IO_BITMAP  /* 20.6.2 */
 			       | CPU_BASED_MOV_DR_EXITING
 			       | CPU_BASED_USE_TSC_OFFSETING   /* 21.3 */
 			);
@@ -2190,11 +2193,50 @@ static struct kvm_arch_ops vmx_arch_ops = {
 
 static int __init vmx_init(void)
 {
-	return kvm_init_arch(&vmx_arch_ops, THIS_MODULE);
+	void *iova;
+	int r;
+
+	vmx_io_bitmap_a = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+	if (!vmx_io_bitmap_a)
+		return -ENOMEM;
+
+	vmx_io_bitmap_b = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+	if (!vmx_io_bitmap_b) {
+		r = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * Allow direct access to the PC debug port (it is often used for I/O
+	 * delays, but the vmexits simply slow things down).
+	 */
+	iova = kmap(vmx_io_bitmap_a);
+	memset(iova, 0xff, PAGE_SIZE);
+	clear_bit(0x80, iova);
+	kunmap(iova);
+
+	iova = kmap(vmx_io_bitmap_b);
+	memset(iova, 0xff, PAGE_SIZE);
+	kunmap(iova);
+
+	r = kvm_init_arch(&vmx_arch_ops, THIS_MODULE);
+	if (r)
+		goto out1;
+
+	return 0;
+
+out1:
+	__free_page(vmx_io_bitmap_b);
+out:
+	__free_page(vmx_io_bitmap_a);
+	return r;
 }
 
 static void __exit vmx_exit(void)
 {
+	__free_page(vmx_io_bitmap_b);
+	__free_page(vmx_io_bitmap_a);
+
 	kvm_exit_arch();
 }
 

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Re: [PATCH][UPDATE] vmx: enable io bitmaps to avoid IO port 0x80 VMEXITs

[Avi Kivity]

He, Qing wrote:
> This is updated version. Because the bitmaps are only needed to be
> mapped at init time, allocating them in high memory if possible saves
> low memory and virtual space.
>
>   

Applied, thanks.  Please include the changelog entry and signed-off-by: 
line in updates in the future (I copied them from your first submission).


-- 
error compiling committee.c: too many arguments to function


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Re: [PATCH][UPDATE] vmx: enable io bitmaps to avoid IO port 0x80 VMEXITs

[He, Qing]

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>-----Original Message-----
>From: Avi Kivity [mailto:avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org]
>Sent: 2007年4月30日 14:47
>To: He, Qing
>Cc: kvm-devel
>Subject: Re: [kvm-devel] [PATCH][UPDATE] vmx: enable io bitmaps to avoid IO port
>0x80 VMEXITs
>
>He, Qing wrote:
>> This is updated version. Because the bitmaps are only needed to be
>> mapped at init time, allocating them in high memory if possible saves
>> low memory and virtual space.
>>
>>
>
>Applied, thanks.  Please include the changelog entry and signed-off-by:
>line in updates in the future (I copied them from your first submission).
Thanks a lot. That's what I meant.

>
>
>--
>error compiling committee.c: too many arguments to function


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