2016-10-07 12:30:58

by Radim Krčmář

[permalink] [raw]
Subject: Re: [PATCH v2 2/3] KVM: VMX: join functions that disable x2apic msr intercepts

2016-09-30 10:29+0200, Paolo Bonzini:
> On 29/09/2016 22:41, Radim Krčmář wrote:
>> for (msr = 0x800; msr <= 0x8ff; msr++) {
>> if (msr == 0x839 /* TMCCT */)
>> continue;
>> - vmx_disable_intercept_msr_read_x2apic(msr, true);
>> + vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);
>> }
>>
>> /* TPR */
>> - vmx_disable_intercept_msr_write_x2apic(0x808, true);
>> + vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
>> /* EOI */
>> - vmx_disable_intercept_msr_write_x2apic(0x80b, true);
>> + vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);
>> /* SELF-IPI */
>> - vmx_disable_intercept_msr_write_x2apic(0x83f, true);
>> + vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);
>>
>> /*
>> * (enable_apicv && !kvm_vcpu_apicv_active()) ||
>> * !enable_apicv
>> */
>> /* TPR */
>> - vmx_disable_intercept_msr_read_x2apic(0x808, false);
>> - vmx_disable_intercept_msr_write_x2apic(0x808, false);
>> + vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
>
> Alternatively you could place the two function calls for 0x808 together:
>
> for (msr = 0x800; msr <= 0x8ff; msr++)
> vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);
>
> /*
> * TPR reads and writes can be virtualized even if virtual interrupt delivery
> * is not in use.
> */
> vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
> vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
>
> /* EOI */
> vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);
>
> /* SELF-IPI */
> vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);

I have performed this change, thanks, and applied to kvm/queue;
please check the complete patch below:
---8<---
vmx_disable_intercept_msr_read_x2apic() and
vmx_disable_intercept_msr_write_x2apic() differed only in the type.
Pass the type to a new function.

[Ordered and commented TPR intercept according to Paolo's suggestion.]
Signed-off-by: Radim Krčmář <[email protected]>
---
arch/x86/kvm/vmx.c | 51 +++++++++++++++------------------------------------
1 file changed, 15 insertions(+), 36 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8c83268f6f4c..69ff1be3db7b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4656,33 +4656,18 @@ static void vmx_disable_intercept_for_msr(u32 msr, bool longmode_only)
msr, MSR_TYPE_R | MSR_TYPE_W);
}

-static void vmx_disable_intercept_msr_read_x2apic(u32 msr, bool apicv_active)
+static void vmx_disable_intercept_msr_x2apic(u32 msr, int type, bool apicv_active)
{
if (apicv_active) {
__vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv,
- msr, MSR_TYPE_R);
+ msr, type);
__vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv,
- msr, MSR_TYPE_R);
+ msr, type);
} else {
__vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
- msr, MSR_TYPE_R);
+ msr, type);
__vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
- msr, MSR_TYPE_R);
- }
-}
-
-static void vmx_disable_intercept_msr_write_x2apic(u32 msr, bool apicv_active)
-{
- if (apicv_active) {
- __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv,
- msr, MSR_TYPE_W);
- __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv,
- msr, MSR_TYPE_W);
- } else {
- __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
- msr, MSR_TYPE_W);
- __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
- msr, MSR_TYPE_W);
+ msr, type);
}
}

@@ -6463,29 +6448,23 @@ static __init int hardware_setup(void)

set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */

- /*
- * enable_apicv && kvm_vcpu_apicv_active()
- */
for (msr = 0x800; msr <= 0x8ff; msr++) {
if (msr == 0x839 /* TMCCT */)
continue;
- vmx_disable_intercept_msr_read_x2apic(msr, true);
+ vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);
}

- /* TPR */
- vmx_disable_intercept_msr_write_x2apic(0x808, true);
- /* EOI */
- vmx_disable_intercept_msr_write_x2apic(0x80b, true);
- /* SELF-IPI */
- vmx_disable_intercept_msr_write_x2apic(0x83f, true);
-
/*
- * (enable_apicv && !kvm_vcpu_apicv_active()) ||
- * !enable_apicv
+ * TPR reads and writes can be virtualized even if virtual interrupt
+ * delivery is not in use.
*/
- /* TPR */
- vmx_disable_intercept_msr_read_x2apic(0x808, false);
- vmx_disable_intercept_msr_write_x2apic(0x808, false);
+ vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
+ vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
+
+ /* EOI */
+ vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);
+ /* SELF-IPI */
+ vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);

if (enable_ept) {
kvm_mmu_set_mask_ptes(VMX_EPT_READABLE_MASK,


2016-10-07 23:43:35

by Wanpeng Li

[permalink] [raw]
Subject: Re: [PATCH v2 2/3] KVM: VMX: join functions that disable x2apic msr intercepts

2016-10-07 20:30 GMT+08:00 Radim Krčmář <[email protected]>:
> 2016-09-30 10:29+0200, Paolo Bonzini:
>> On 29/09/2016 22:41, Radim Krčmář wrote:
>>> for (msr = 0x800; msr <= 0x8ff; msr++) {
>>> if (msr == 0x839 /* TMCCT */)
>>> continue;
>>> - vmx_disable_intercept_msr_read_x2apic(msr, true);
>>> + vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);
>>> }
>>>
>>> /* TPR */
>>> - vmx_disable_intercept_msr_write_x2apic(0x808, true);
>>> + vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
>>> /* EOI */
>>> - vmx_disable_intercept_msr_write_x2apic(0x80b, true);
>>> + vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);
>>> /* SELF-IPI */
>>> - vmx_disable_intercept_msr_write_x2apic(0x83f, true);
>>> + vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);
>>>
>>> /*
>>> * (enable_apicv && !kvm_vcpu_apicv_active()) ||
>>> * !enable_apicv
>>> */
>>> /* TPR */
>>> - vmx_disable_intercept_msr_read_x2apic(0x808, false);
>>> - vmx_disable_intercept_msr_write_x2apic(0x808, false);
>>> + vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
>>
>> Alternatively you could place the two function calls for 0x808 together:
>>
>> for (msr = 0x800; msr <= 0x8ff; msr++)
>> vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);
>>
>> /*
>> * TPR reads and writes can be virtualized even if virtual interrupt delivery
>> * is not in use.
>> */
>> vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
>> vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
>>
>> /* EOI */
>> vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);
>>
>> /* SELF-IPI */
>> vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);
>
> I have performed this change, thanks, and applied to kvm/queue;
> please check the complete patch below:
> ---8<---
> vmx_disable_intercept_msr_read_x2apic() and
> vmx_disable_intercept_msr_write_x2apic() differed only in the type.
> Pass the type to a new function.
>
> [Ordered and commented TPR intercept according to Paolo's suggestion.]

Looks good to me. :)

Regards,
Wanpeng Li

> Signed-off-by: Radim Krčmář <[email protected]>
> ---
> arch/x86/kvm/vmx.c | 51 +++++++++++++++------------------------------------
> 1 file changed, 15 insertions(+), 36 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 8c83268f6f4c..69ff1be3db7b 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -4656,33 +4656,18 @@ static void vmx_disable_intercept_for_msr(u32 msr, bool longmode_only)
> msr, MSR_TYPE_R | MSR_TYPE_W);
> }
>
> -static void vmx_disable_intercept_msr_read_x2apic(u32 msr, bool apicv_active)
> +static void vmx_disable_intercept_msr_x2apic(u32 msr, int type, bool apicv_active)
> {
> if (apicv_active) {
> __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv,
> - msr, MSR_TYPE_R);
> + msr, type);
> __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv,
> - msr, MSR_TYPE_R);
> + msr, type);
> } else {
> __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
> - msr, MSR_TYPE_R);
> + msr, type);
> __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
> - msr, MSR_TYPE_R);
> - }
> -}
> -
> -static void vmx_disable_intercept_msr_write_x2apic(u32 msr, bool apicv_active)
> -{
> - if (apicv_active) {
> - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv,
> - msr, MSR_TYPE_W);
> - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv,
> - msr, MSR_TYPE_W);
> - } else {
> - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
> - msr, MSR_TYPE_W);
> - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
> - msr, MSR_TYPE_W);
> + msr, type);
> }
> }
>
> @@ -6463,29 +6448,23 @@ static __init int hardware_setup(void)
>
> set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */
>
> - /*
> - * enable_apicv && kvm_vcpu_apicv_active()
> - */
> for (msr = 0x800; msr <= 0x8ff; msr++) {
> if (msr == 0x839 /* TMCCT */)
> continue;
> - vmx_disable_intercept_msr_read_x2apic(msr, true);
> + vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);
> }
>
> - /* TPR */
> - vmx_disable_intercept_msr_write_x2apic(0x808, true);
> - /* EOI */
> - vmx_disable_intercept_msr_write_x2apic(0x80b, true);
> - /* SELF-IPI */
> - vmx_disable_intercept_msr_write_x2apic(0x83f, true);
> -
> /*
> - * (enable_apicv && !kvm_vcpu_apicv_active()) ||
> - * !enable_apicv
> + * TPR reads and writes can be virtualized even if virtual interrupt
> + * delivery is not in use.
> */
> - /* TPR */
> - vmx_disable_intercept_msr_read_x2apic(0x808, false);
> - vmx_disable_intercept_msr_write_x2apic(0x808, false);
> + vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
> + vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
> +
> + /* EOI */
> + vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);
> + /* SELF-IPI */
> + vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);
>
> if (enable_ept) {
> kvm_mmu_set_mask_ptes(VMX_EPT_READABLE_MASK,