* [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled
@ 2017-10-08 2:35 Wanpeng Li
2017-10-08 2:35 ` [PATCH 2/2] KVM: X86: XCR0 should be set to the fixed value on vCPU reset Wanpeng Li
2017-10-08 22:35 ` [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled Jim Mattson
0 siblings, 2 replies; 6+ messages in thread
From: Wanpeng Li @ 2017-10-08 2:35 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: Paolo Bonzini, Radim Krčmář, Wanpeng Li
From: Wanpeng Li <wanpeng.li@hotmail.com>
SDM mentioned:
"If either the “unrestricted guest” VM-execution control or the “mode-based
execute control for EPT” VM- execution control is 1, the “enable EPT”
VM-execution control must also be 1."
However, we can still observe unrestricted_guest is Y after inserting the kvm-intel.ko
w/ ept=N. It depends on later starts a guest in order that the function
vmx_compute_secondary_exec_control() can be executed, then both the module parameter
and exec control fields will be amended.
This patch fixes it by amending module parameter immediately during vmcs data setup.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
arch/x86/kvm/vmx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 244e366..3e664ca 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6737,7 +6737,7 @@ static __init int hardware_setup(void)
if (!cpu_has_vmx_ept_ad_bits() || !enable_ept)
enable_ept_ad_bits = 0;
- if (!cpu_has_vmx_unrestricted_guest())
+ if (!cpu_has_vmx_unrestricted_guest() || !enable_ept)
enable_unrestricted_guest = 0;
if (!cpu_has_vmx_flexpriority())
--
2.7.4
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/2] KVM: X86: XCR0 should be set to the fixed value on vCPU reset
2017-10-08 2:35 [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled Wanpeng Li
@ 2017-10-08 2:35 ` Wanpeng Li
2017-10-08 22:36 ` Jim Mattson
2017-10-09 8:04 ` Paolo Bonzini
2017-10-08 22:35 ` [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled Jim Mattson
1 sibling, 2 replies; 6+ messages in thread
From: Wanpeng Li @ 2017-10-08 2:35 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: Paolo Bonzini, Radim Krčmář, Wanpeng Li
From: Wanpeng Li <wanpeng.li@hotmail.com>
SDM section 2.6 mentioned:
After reset, all bits (except bit 0) in XCR0 are cleared to zero; XCR0[0] is set to 1.
This patch sets XCRO to the 0x1 after vCPU reset.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
arch/x86/kvm/x86.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b0d2915..c784cd6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7816,6 +7816,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
vcpu->arch.regs_avail = ~0;
vcpu->arch.regs_dirty = ~0;
+ vcpu->arch.xcr0 = XFEATURE_MASK_FP;
+
kvm_x86_ops->vcpu_reset(vcpu, init_event);
}
--
2.7.4
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] KVM: X86: XCR0 should be set to the fixed value on vCPU reset
2017-10-08 2:35 ` [PATCH 2/2] KVM: X86: XCR0 should be set to the fixed value on vCPU reset Wanpeng Li
@ 2017-10-08 22:36 ` Jim Mattson
2017-10-09 8:04 ` Paolo Bonzini
1 sibling, 0 replies; 6+ messages in thread
From: Jim Mattson @ 2017-10-08 22:36 UTC (permalink / raw)
To: Wanpeng Li
Cc: LKML, kvm list, Paolo Bonzini, Radim Krčmář, Wanpeng Li
Reviewed-by: Jim Mattson <jmattson@google.com>
On Sat, Oct 7, 2017 at 7:35 PM, Wanpeng Li <kernellwp@gmail.com> wrote:
> From: Wanpeng Li <wanpeng.li@hotmail.com>
>
> SDM section 2.6 mentioned:
>
> After reset, all bits (except bit 0) in XCR0 are cleared to zero; XCR0[0] is set to 1.
>
> This patch sets XCRO to the 0x1 after vCPU reset.
>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
> ---
> arch/x86/kvm/x86.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index b0d2915..c784cd6 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -7816,6 +7816,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
> vcpu->arch.regs_avail = ~0;
> vcpu->arch.regs_dirty = ~0;
>
> + vcpu->arch.xcr0 = XFEATURE_MASK_FP;
> +
> kvm_x86_ops->vcpu_reset(vcpu, init_event);
> }
>
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] KVM: X86: XCR0 should be set to the fixed value on vCPU reset
2017-10-08 2:35 ` [PATCH 2/2] KVM: X86: XCR0 should be set to the fixed value on vCPU reset Wanpeng Li
2017-10-08 22:36 ` Jim Mattson
@ 2017-10-09 8:04 ` Paolo Bonzini
1 sibling, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2017-10-09 8:04 UTC (permalink / raw)
To: Wanpeng Li, linux-kernel, kvm; +Cc: Radim Krčmář, Wanpeng Li
On 08/10/2017 04:35, Wanpeng Li wrote:
> From: Wanpeng Li <wanpeng.li@hotmail.com>
>
> SDM section 2.6 mentioned:
>
> After reset, all bits (except bit 0) in XCR0 are cleared to zero; XCR0[0] is set to 1.
>
> This patch sets XCRO to the 0x1 after vCPU reset.
>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
> ---
> arch/x86/kvm/x86.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index b0d2915..c784cd6 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -7816,6 +7816,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
> vcpu->arch.regs_avail = ~0;
> vcpu->arch.regs_dirty = ~0;
>
> + vcpu->arch.xcr0 = XFEATURE_MASK_FP;
XCR0 is unchanged by INIT. There are many other registers that are
zeroed by RESET by not INIT; KVM pretty much relies on userspace doing
that. On the other hand, it's useful to zero here those registers that
are zeroed by INIT as well:
- XSS
- BNDCFGU, BND0-BND3, BNDCFGS (BNDCFGS probably would go in
vmx_vcpu_reset, the others are in vcpu->arch.guest_fpu.state.xsave).
> kvm_x86_ops->vcpu_reset(vcpu, init_event);
> }
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled
2017-10-08 2:35 [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled Wanpeng Li
2017-10-08 2:35 ` [PATCH 2/2] KVM: X86: XCR0 should be set to the fixed value on vCPU reset Wanpeng Li
@ 2017-10-08 22:35 ` Jim Mattson
2017-10-09 7:54 ` Paolo Bonzini
1 sibling, 1 reply; 6+ messages in thread
From: Jim Mattson @ 2017-10-08 22:35 UTC (permalink / raw)
To: Wanpeng Li
Cc: LKML, kvm list, Paolo Bonzini, Radim Krčmář, Wanpeng Li
If it were me, I'd apply De Morgan to that expression, but the logic looks fine.
Reviewed-by: Jim Mattson <jmattson@google.com>
On Sat, Oct 7, 2017 at 7:35 PM, Wanpeng Li <kernellwp@gmail.com> wrote:
> From: Wanpeng Li <wanpeng.li@hotmail.com>
>
> SDM mentioned:
>
> "If either the “unrestricted guest” VM-execution control or the “mode-based
> execute control for EPT” VM- execution control is 1, the “enable EPT”
> VM-execution control must also be 1."
>
> However, we can still observe unrestricted_guest is Y after inserting the kvm-intel.ko
> w/ ept=N. It depends on later starts a guest in order that the function
> vmx_compute_secondary_exec_control() can be executed, then both the module parameter
> and exec control fields will be amended.
>
> This patch fixes it by amending module parameter immediately during vmcs data setup.
>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
> ---
> arch/x86/kvm/vmx.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 244e366..3e664ca 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -6737,7 +6737,7 @@ static __init int hardware_setup(void)
> if (!cpu_has_vmx_ept_ad_bits() || !enable_ept)
> enable_ept_ad_bits = 0;
>
> - if (!cpu_has_vmx_unrestricted_guest())
> + if (!cpu_has_vmx_unrestricted_guest() || !enable_ept)
> enable_unrestricted_guest = 0;
>
> if (!cpu_has_vmx_flexpriority())
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled
2017-10-08 22:35 ` [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled Jim Mattson
@ 2017-10-09 7:54 ` Paolo Bonzini
0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2017-10-09 7:54 UTC (permalink / raw)
To: Jim Mattson, Wanpeng Li
Cc: LKML, kvm list, Radim Krčmář, Wanpeng Li
On 09/10/2017 00:35, Jim Mattson wrote:
> If it were me, I'd apply De Morgan to that expression, but the logic looks fine.
>
> Reviewed-by: Jim Mattson <jmattson@google.com>
I'm okay with the way Wanpeng wrote it, but as a follow up this:
if (!cpu_has_vmx_ept() ||
!cpu_has_vmx_ept_4levels() ||
!cpu_has_vmx_ept_mt_wb()) {
enable_ept = 0;
enable_unrestricted_guest = 0;
enable_ept_ad_bits = 0;
}
can be reduced to just "enable_ept = 0".
Paolo
> On Sat, Oct 7, 2017 at 7:35 PM, Wanpeng Li <kernellwp@gmail.com> wrote:
>> From: Wanpeng Li <wanpeng.li@hotmail.com>
>>
>> SDM mentioned:
>>
>> "If either the “unrestricted guest” VM-execution control or the “mode-based
>> execute control for EPT” VM- execution control is 1, the “enable EPT”
>> VM-execution control must also be 1."
>>
>> However, we can still observe unrestricted_guest is Y after inserting the kvm-intel.ko
>> w/ ept=N. It depends on later starts a guest in order that the function
>> vmx_compute_secondary_exec_control() can be executed, then both the module parameter
>> and exec control fields will be amended.
>>
>> This patch fixes it by amending module parameter immediately during vmcs data setup.
>>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Cc: Radim Krčmář <rkrcmar@redhat.com>
>> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
>> ---
>> arch/x86/kvm/vmx.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index 244e366..3e664ca 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -6737,7 +6737,7 @@ static __init int hardware_setup(void)
>> if (!cpu_has_vmx_ept_ad_bits() || !enable_ept)
>> enable_ept_ad_bits = 0;
>>
>> - if (!cpu_has_vmx_unrestricted_guest())
>> + if (!cpu_has_vmx_unrestricted_guest() || !enable_ept)
>> enable_unrestricted_guest = 0;
>>
>> if (!cpu_has_vmx_flexpriority())
>> --
>> 2.7.4
>>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-10-09 8:05 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-10-08 2:35 [PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled Wanpeng Li
2017-10-08 2:35 ` [PATCH 2/2] KVM: X86: XCR0 should be set to the fixed value on vCPU reset Wanpeng Li
2017-10-08 22:36 ` Jim Mattson
2017-10-09 8:04 ` Paolo Bonzini
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2017-10-09 7:54 ` Paolo Bonzini
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