2014-12-06 15:02:31

by Bandan Das

[permalink] [raw]

Subject: [PATCH] KVM: nVMX: Disable unrestricted mode if ept=0

---

If L0 has disabled EPT, don't advertise unrestricted
mode at all since it depends on EPT to run real mode code.

Signed-off-by: Bandan Das <[email protected]>
---
arch/x86/kvm/vmx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3e556c6..ed70394 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2377,12 +2377,12 @@ static __init void nested_vmx_setup_ctls_msrs(void)
nested_vmx_secondary_ctls_low = 0;
nested_vmx_secondary_ctls_high &=
SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
- SECONDARY_EXEC_UNRESTRICTED_GUEST |
SECONDARY_EXEC_WBINVD_EXITING;

if (enable_ept) {
/* nested EPT: emulate EPT also to L1 */
- nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT;
+ nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT |
+ SECONDARY_EXEC_UNRESTRICTED_GUEST;
nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT |
VMX_EPTP_WB_BIT | VMX_EPT_2MB_PAGE_BIT |
VMX_EPT_INVEPT_BIT;
--
1.9.3

2014-12-07 10:22:31

by Jan Kiszka

[permalink] [raw]

Subject: Re: [PATCH] KVM: nVMX: Disable unrestricted mode if ept=0

---

On 2014-12-06 16:02, Bandan Das wrote:
>
> If L0 has disabled EPT, don't advertise unrestricted
> mode at all since it depends on EPT to run real mode code.
>
> Signed-off-by: Bandan Das <[email protected]>
> ---
> arch/x86/kvm/vmx.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 3e556c6..ed70394 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2377,12 +2377,12 @@ static __init void nested_vmx_setup_ctls_msrs(void)
> nested_vmx_secondary_ctls_low = 0;
> nested_vmx_secondary_ctls_high &=
> SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
> - SECONDARY_EXEC_UNRESTRICTED_GUEST |
> SECONDARY_EXEC_WBINVD_EXITING;
>
> if (enable_ept) {
> /* nested EPT: emulate EPT also to L1 */
> - nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT;
> + nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT |
> + SECONDARY_EXEC_UNRESTRICTED_GUEST;
> nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT |
> VMX_EPTP_WB_BIT | VMX_EPT_2MB_PAGE_BIT |
> VMX_EPT_INVEPT_BIT;
>

Reviewed-by: Jan Kiszka <[email protected]>

Jan

---

Attachments:

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2014-12-10 12:06:59

by Paolo Bonzini

[permalink] [raw]

Subject: Re: [PATCH] KVM: nVMX: Disable unrestricted mode if ept=0

---

On 06/12/2014 16:02, Bandan Das wrote:
>
> If L0 has disabled EPT, don't advertise unrestricted
> mode at all since it depends on EPT to run real mode code.
>
> Signed-off-by: Bandan Das <[email protected]>
> ---
> arch/x86/kvm/vmx.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 3e556c6..ed70394 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2377,12 +2377,12 @@ static __init void nested_vmx_setup_ctls_msrs(void)
> nested_vmx_secondary_ctls_low = 0;
> nested_vmx_secondary_ctls_high &=
> SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
> - SECONDARY_EXEC_UNRESTRICTED_GUEST |
> SECONDARY_EXEC_WBINVD_EXITING;
>
> if (enable_ept) {
> /* nested EPT: emulate EPT also to L1 */
> - nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT;
> + nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT |
> + SECONDARY_EXEC_UNRESTRICTED_GUEST;
> nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT |
> VMX_EPTP_WB_BIT | VMX_EPT_2MB_PAGE_BIT |
> VMX_EPT_INVEPT_BIT;
>

Thanks, applied with

Fixes: 92fbc7b195b824e201d9f06f2b93105f72384d65
Cc: [email protected]

Paolo