| Message ID | 1238164319-16092-8-git-send-email-joerg.roedel@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Joerg Roedel wrote: > If userspace knows that the kernel part supports 1GB pages it can enable > the corresponding cpuid bit so that guests actually use GB pages. > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index a1df2a3..6593198 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -542,6 +542,8 @@ struct kvm_x86_ops { > int (*set_tss_addr)(struct kvm *kvm, unsigned int addr); > int (*get_tdp_level)(void); > int (*get_mt_mask_shift)(void); > + > + bool (*gb_page_enable)(void); > }; > Should enable unconditionally. Of course we need to find the shadow bug first, may be the has_wrprotected thingy. > diff --git a/include/linux/kvm.h b/include/linux/kvm.h > index ee755e2..e79eb26 100644 > --- a/include/linux/kvm.h > +++ b/include/linux/kvm.h > @@ -413,6 +413,7 @@ struct kvm_trace_rec { > #define KVM_CAP_DEVICE_MSIX 28 > #endif > #define KVM_CAP_ASSIGN_DEV_IRQ 29 > +#define KVM_CAP_1GB_PAGES 30 > > #ifdef KVM_CAP_IRQ_ROUTING > > Need KVM_GET_SUPPORTED_CPUID2 support as well.
On Sun, Mar 29, 2009 at 02:54:31PM +0300, Avi Kivity wrote: > Joerg Roedel wrote: >> If userspace knows that the kernel part supports 1GB pages it can enable >> the corresponding cpuid bit so that guests actually use GB pages. >> > >> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h >> index a1df2a3..6593198 100644 >> --- a/arch/x86/include/asm/kvm_host.h >> +++ b/arch/x86/include/asm/kvm_host.h >> @@ -542,6 +542,8 @@ struct kvm_x86_ops { >> int (*set_tss_addr)(struct kvm *kvm, unsigned int addr); >> int (*get_tdp_level)(void); >> int (*get_mt_mask_shift)(void); >> + >> + bool (*gb_page_enable)(void); >> }; >> > > Should enable unconditionally. Of course we need to find the shadow bug > first, may be the has_wrprotected thingy. This was the original plan. But how about VMX with EPT enabled? I am not sure but I think this configuration will not support gbpages? Joerg -- 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
Joerg Roedel wrote: >>> int (*set_tss_addr)(struct kvm *kvm, unsigned int addr); >>> int (*get_tdp_level)(void); >>> int (*get_mt_mask_shift)(void); >>> + >>> + bool (*gb_page_enable)(void); >>> }; >>> >>> >> Should enable unconditionally. Of course we need to find the shadow bug >> first, may be the has_wrprotected thingy. >> > > This was the original plan. But how about VMX with EPT enabled? I am not > sure but I think this configuration will not support gbpages? > > You're right. Let's have a ->max_host_page_level() to handle that. It's 0.5T pages ready, too.
On Sun, Mar 29, 2009 at 03:49:11PM +0300, Avi Kivity wrote: > Joerg Roedel wrote: >>>> int (*set_tss_addr)(struct kvm *kvm, unsigned int addr); >>>> int (*get_tdp_level)(void); >>>> int (*get_mt_mask_shift)(void); >>>> + >>>> + bool (*gb_page_enable)(void); >>>> }; >>>> >>> Should enable unconditionally. Of course we need to find the shadow >>> bug first, may be the has_wrprotected thingy. >>> >> >> This was the original plan. But how about VMX with EPT enabled? I am not >> sure but I think this configuration will not support gbpages? >> >> > > You're right. Let's have a ->max_host_page_level() to handle that. > It's 0.5T pages ready, too. Ok I will change that together with the page_size -> page_level chhanges. But I doubt that there will ever be 0.5T pages ;) Joerg -- 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
Joerg Roedel wrote: > Ok I will change that together with the page_size -> page_level > chhanges. But I doubt that there will ever be 0.5T pages ;) > We're bloating at a rate of 1 bit per 1-2 years, so we have 8-16 years to prepare.
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a1df2a3..6593198 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -542,6 +542,8 @@ struct kvm_x86_ops { int (*set_tss_addr)(struct kvm *kvm, unsigned int addr); int (*get_tdp_level)(void); int (*get_mt_mask_shift)(void); + + bool (*gb_page_enable)(void); }; extern struct kvm_x86_ops *kvm_x86_ops; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 1fcbc17..d140686 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2604,6 +2604,11 @@ static int svm_get_mt_mask_shift(void) return 0; } +static bool svm_gb_page_enable(void) +{ + return npt_enabled; +} + static struct kvm_x86_ops svm_x86_ops = { .cpu_has_kvm_support = has_svm, .disabled_by_bios = is_disabled, @@ -2661,6 +2666,8 @@ static struct kvm_x86_ops svm_x86_ops = { .set_tss_addr = svm_set_tss_addr, .get_tdp_level = get_npt_level, .get_mt_mask_shift = svm_get_mt_mask_shift, + + .gb_page_enable = svm_gb_page_enable, }; static int __init svm_init(void) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 37ae13d..e54af3f 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3647,6 +3647,11 @@ static int vmx_get_mt_mask_shift(void) return VMX_EPT_MT_EPTE_SHIFT; } +static bool vmx_gb_page_enable(void) +{ + return false; +} + static struct kvm_x86_ops vmx_x86_ops = { .cpu_has_kvm_support = cpu_has_kvm_support, .disabled_by_bios = vmx_disabled_by_bios, @@ -3702,6 +3707,8 @@ static struct kvm_x86_ops vmx_x86_ops = { .set_tss_addr = vmx_set_tss_addr, .get_tdp_level = get_ept_level, .get_mt_mask_shift = vmx_get_mt_mask_shift, + + .gb_page_enable = vmx_gb_page_enable, }; static int __init vmx_init(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ae4918c..c94f231 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1009,7 +1009,7 @@ out: int kvm_dev_ioctl_check_extension(long ext) { - int r; + int r = 0; switch (ext) { case KVM_CAP_IRQCHIP: @@ -1027,6 +1027,10 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_ASSIGN_DEV_IRQ: r = 1; break; + case KVM_CAP_1GB_PAGES: + if (kvm_x86_ops->gb_page_enable()) + r = 1; + break; case KVM_CAP_COALESCED_MMIO: r = KVM_COALESCED_MMIO_PAGE_OFFSET; break; diff --git a/include/linux/kvm.h b/include/linux/kvm.h index ee755e2..e79eb26 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -413,6 +413,7 @@ struct kvm_trace_rec { #define KVM_CAP_DEVICE_MSIX 28 #endif #define KVM_CAP_ASSIGN_DEV_IRQ 29 +#define KVM_CAP_1GB_PAGES 30 #ifdef KVM_CAP_IRQ_ROUTING
If userspace knows that the kernel part supports 1GB pages it can enable the corresponding cpuid bit so that guests actually use GB pages. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/svm.c | 7 +++++++ arch/x86/kvm/vmx.c | 7 +++++++ arch/x86/kvm/x86.c | 6 +++++- include/linux/kvm.h | 1 + 5 files changed, 22 insertions(+), 1 deletions(-)