| Message ID | 1247767342-13519-3-git-send-email-jordan.l.justen@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jul 16, 2009 at 11:02:22AM -0700, Jordan Justen wrote: > Although VMX_EPT_IDENTITY_PAGETABLE_ADDR does not appear to be used within > qemu-kvm, this change mirrors a similar change in the kernel kvm code. > > The purpose is to move the KVM 'EPT Identity Pages' from: > 0xfffbc000-0xfffbcfff > to: > 0xfeffc000-0xfeffcfff > > The step is required to free up the 0xff000000-0xffffffff (16MB) range > for use with bios.bin. > > The KVM kernel change depends upon a change to kvm/bios/rombios.c so the bios > INT15-E820 function will properly reserve the new location. > > Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> > --- > kvm/include/x86/asm/vmx.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/kvm/include/x86/asm/vmx.h b/kvm/include/x86/asm/vmx.h > index df8d4f9..99e2bb9 100644 > --- a/kvm/include/x86/asm/vmx.h > +++ b/kvm/include/x86/asm/vmx.h > @@ -403,7 +403,7 @@ enum vmcs_field { > #define VMX_EPT_EXECUTABLE_MASK 0x4ull > #define VMX_EPT_IGMT_BIT (1ull << 6) > > -#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfffbc000ul > +#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfeffc000ul Won't this conflict with an older BIOS? (the e820 reserved entry on older qemu-kvm+bios will not cover the EPT identity table on kernels with this patch). Perhaps add a new ioctl (similar to the tss one) to so userspace can set the address? > > > #define ASM_VMX_VMCLEAR_RAX ".byte 0x66, 0x0f, 0xc7, 0x30" > -- > 1.6.0.4 > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2009-07-16 at 11:18 -0700, Marcelo Tosatti wrote: > On Thu, Jul 16, 2009 at 11:02:22AM -0700, Jordan Justen wrote: > > Although VMX_EPT_IDENTITY_PAGETABLE_ADDR does not appear to be used within > > qemu-kvm, this change mirrors a similar change in the kernel kvm code. > > > > The purpose is to move the KVM 'EPT Identity Pages' from: > > 0xfffbc000-0xfffbcfff > > to: > > 0xfeffc000-0xfeffcfff > > > > The step is required to free up the 0xff000000-0xffffffff (16MB) range > > for use with bios.bin. > > > > The KVM kernel change depends upon a change to kvm/bios/rombios.c so the bios > > INT15-E820 function will properly reserve the new location. > > > > Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> > > --- > > kvm/include/x86/asm/vmx.h | 2 +- > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > diff --git a/kvm/include/x86/asm/vmx.h b/kvm/include/x86/asm/vmx.h > > index df8d4f9..99e2bb9 100644 > > --- a/kvm/include/x86/asm/vmx.h > > +++ b/kvm/include/x86/asm/vmx.h > > @@ -403,7 +403,7 @@ enum vmcs_field { > > #define VMX_EPT_EXECUTABLE_MASK 0x4ull > > #define VMX_EPT_IGMT_BIT (1ull << 6) > > > > -#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfffbc000ul > > +#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfeffc000ul > > Won't this conflict with an older BIOS? (the e820 reserved entry on > older qemu-kvm+bios will not cover the EPT identity table on kernels > with this patch). > > Perhaps add a new ioctl (similar to the tss one) to so userspace can set > the address? I am not very familiar with the reasons why the EPT identity page-table setup is happening within the kernel. As it stands, there is the shared knowledge that the qemu-kvm bios just happens to know that the kvm kernel code has reserved a particular page of the address space. It would be much easier to coordinate all the pieces if it were all setup on the qemu-kvm side. Is this possible? > > > > > > #define ASM_VMX_VMCLEAR_RAX ".byte 0x66, 0x0f, 0xc7, 0x30" > > -- > > 1.6.0.4 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe kvm" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jul 16, 2009 at 11:48:46AM -0700, Jordan Justen wrote: > On Thu, 2009-07-16 at 11:18 -0700, Marcelo Tosatti wrote: > > On Thu, Jul 16, 2009 at 11:02:22AM -0700, Jordan Justen wrote: > > > Although VMX_EPT_IDENTITY_PAGETABLE_ADDR does not appear to be used within > > > qemu-kvm, this change mirrors a similar change in the kernel kvm code. > > > > > > The purpose is to move the KVM 'EPT Identity Pages' from: > > > 0xfffbc000-0xfffbcfff > > > to: > > > 0xfeffc000-0xfeffcfff > > > > > > The step is required to free up the 0xff000000-0xffffffff (16MB) range > > > for use with bios.bin. > > > > > > The KVM kernel change depends upon a change to kvm/bios/rombios.c so the bios > > > INT15-E820 function will properly reserve the new location. > > > > > > Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> > > > --- > > > kvm/include/x86/asm/vmx.h | 2 +- > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > diff --git a/kvm/include/x86/asm/vmx.h b/kvm/include/x86/asm/vmx.h > > > index df8d4f9..99e2bb9 100644 > > > --- a/kvm/include/x86/asm/vmx.h > > > +++ b/kvm/include/x86/asm/vmx.h > > > @@ -403,7 +403,7 @@ enum vmcs_field { > > > #define VMX_EPT_EXECUTABLE_MASK 0x4ull > > > #define VMX_EPT_IGMT_BIT (1ull << 6) > > > > > > -#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfffbc000ul > > > +#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfeffc000ul > > > > Won't this conflict with an older BIOS? (the e820 reserved entry on > > older qemu-kvm+bios will not cover the EPT identity table on kernels > > with this patch). > > > > Perhaps add a new ioctl (similar to the tss one) to so userspace can set > > the address? > > I am not very familiar with the reasons why the EPT identity > page-table setup is happening within the kernel. > > As it stands, there is the shared knowledge that the qemu-kvm bios > just happens to know that the kvm kernel code has reserved a > particular page of the address space. > > It would be much easier to coordinate all the pieces if it were > all setup on the qemu-kvm side. > > Is this possible? It is possible but all of the EPT implementation is in the kernel, so it does not make much sense to have the details of the identity table in qemu-kvm. The address of it though can be controlled by qemu-kvm. Sheng? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Friday 17 July 2009 03:14:54 Marcelo Tosatti wrote: > On Thu, Jul 16, 2009 at 11:48:46AM -0700, Jordan Justen wrote: > > On Thu, 2009-07-16 at 11:18 -0700, Marcelo Tosatti wrote: > > > On Thu, Jul 16, 2009 at 11:02:22AM -0700, Jordan Justen wrote: > > > > Although VMX_EPT_IDENTITY_PAGETABLE_ADDR does not appear to be used > > > > within qemu-kvm, this change mirrors a similar change in the kernel > > > > kvm code. > > > > > > > > The purpose is to move the KVM 'EPT Identity Pages' from: > > > > 0xfffbc000-0xfffbcfff > > > > to: > > > > 0xfeffc000-0xfeffcfff > > > > > > > > The step is required to free up the 0xff000000-0xffffffff (16MB) > > > > range for use with bios.bin. > > > > > > > > The KVM kernel change depends upon a change to kvm/bios/rombios.c so > > > > the bios INT15-E820 function will properly reserve the new location. > > > > > > > > Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> > > > > --- > > > > kvm/include/x86/asm/vmx.h | 2 +- > > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > > > diff --git a/kvm/include/x86/asm/vmx.h b/kvm/include/x86/asm/vmx.h > > > > index df8d4f9..99e2bb9 100644 > > > > --- a/kvm/include/x86/asm/vmx.h > > > > +++ b/kvm/include/x86/asm/vmx.h > > > > @@ -403,7 +403,7 @@ enum vmcs_field { > > > > #define VMX_EPT_EXECUTABLE_MASK 0x4ull > > > > #define VMX_EPT_IGMT_BIT (1ull << 6) > > > > > > > > -#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfffbc000ul > > > > +#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfeffc000ul > > > > > > Won't this conflict with an older BIOS? (the e820 reserved entry on > > > older qemu-kvm+bios will not cover the EPT identity table on kernels > > > with this patch). > > > > > > Perhaps add a new ioctl (similar to the tss one) to so userspace can > > > set the address? > > > > I am not very familiar with the reasons why the EPT identity > > page-table setup is happening within the kernel. > > > > As it stands, there is the shared knowledge that the qemu-kvm bios > > just happens to know that the kvm kernel code has reserved a > > particular page of the address space. > > > > It would be much easier to coordinate all the pieces if it were > > all setup on the qemu-kvm side. > > > > Is this possible? > > It is possible but all of the EPT implementation is in the kernel, so it > does not make much sense to have the details of the identity table in > qemu-kvm. > > The address of it though can be controlled by qemu-kvm. > > Sheng? Put the identity map into kernel space because we want older version QEmu can also work with EPT. Yes, we need a new CAP for address. Would do it soon.
diff --git a/kvm/include/x86/asm/vmx.h b/kvm/include/x86/asm/vmx.h index df8d4f9..99e2bb9 100644 --- a/kvm/include/x86/asm/vmx.h +++ b/kvm/include/x86/asm/vmx.h @@ -403,7 +403,7 @@ enum vmcs_field { #define VMX_EPT_EXECUTABLE_MASK 0x4ull #define VMX_EPT_IGMT_BIT (1ull << 6) -#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfffbc000ul +#define VMX_EPT_IDENTITY_PAGETABLE_ADDR 0xfeffc000ul #define ASM_VMX_VMCLEAR_RAX ".byte 0x66, 0x0f, 0xc7, 0x30"
Although VMX_EPT_IDENTITY_PAGETABLE_ADDR does not appear to be used within qemu-kvm, this change mirrors a similar change in the kernel kvm code. The purpose is to move the KVM 'EPT Identity Pages' from: 0xfffbc000-0xfffbcfff to: 0xfeffc000-0xfeffcfff The step is required to free up the 0xff000000-0xffffffff (16MB) range for use with bios.bin. The KVM kernel change depends upon a change to kvm/bios/rombios.c so the bios INT15-E820 function will properly reserve the new location. Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> --- kvm/include/x86/asm/vmx.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)