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| author | Marcelo Tosatti <mtosatti@redhat.com> | 2009-06-11 19:07:44 +0400 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-09-10 09:32:56 +0400 |
| commit | 54dee9933e8d93589ad63ec3d6be39f1921b0767 (patch) | |
| tree | 77aa79604ddfb6f842e582e7b8ce7cdbc54b2060 | |
| parent | 68f89400bc92421d6da22e1ec8e3ec599c3c8244 (diff) | |
| download | linux-54dee9933e8d93589ad63ec3d6be39f1921b0767.tar.xz | |
KVM: VMX: conditionally disable 2M pages
Disable usage of 2M pages if VMX_EPT_2MB_PAGE_BIT (bit 16) is clear
in MSR_IA32_VMX_EPT_VPID_CAP and EPT is enabled.
[avi: s/largepages_disabled/largepages_enabled/ to avoid negative logic]
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 3 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 1 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 14 |
3 files changed, 16 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 94c07ada103e..fc8d49c6bc51 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1381,6 +1381,9 @@ static __init int hardware_setup(void) if (!cpu_has_vmx_tpr_shadow()) kvm_x86_ops->update_cr8_intercept = NULL; + if (enable_ept && !cpu_has_vmx_ept_2m_page()) + kvm_disable_largepages(); + return alloc_kvm_area(); } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index c6e4d02067fe..6988858dc56e 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -224,6 +224,7 @@ int kvm_arch_set_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem, struct kvm_memory_slot old, int user_alloc); +void kvm_disable_largepages(void); void kvm_arch_flush_shadow(struct kvm *kvm); gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn); struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 777fe533cfe7..48d5e697bf44 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -85,6 +85,8 @@ static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, static bool kvm_rebooting; +static bool largepages_enabled = true; + #ifdef KVM_CAP_DEVICE_ASSIGNMENT static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head, int assigned_dev_id) @@ -1174,9 +1176,11 @@ int __kvm_set_memory_region(struct kvm *kvm, ugfn = new.userspace_addr >> PAGE_SHIFT; /* * If the gfn and userspace address are not aligned wrt each - * other, disable large page support for this slot + * other, or if explicitly asked to, disable large page + * support for this slot */ - if ((base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE - 1)) + if ((base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE - 1) || + !largepages_enabled) for (i = 0; i < largepages; ++i) new.lpage_info[i].write_count = 1; } @@ -1291,6 +1295,12 @@ out: return r; } +void kvm_disable_largepages(void) +{ + largepages_enabled = false; +} +EXPORT_SYMBOL_GPL(kvm_disable_largepages); + int is_error_page(struct page *page) { return page == bad_page; |