This patch contains code to prepare the VMCS which can be used to actually
run the L2 guest, vmcs02. prepare_vmcs02 appropriately merges the information
in vmcs12 (the vmcs that L1 built for L2) and in vmcs01 (the vmcs that we
built for L1).

VMREAD/WRITE can only access one VMCS at a time (the "current" VMCS), which
makes it difficult for us to read from vmcs01 while writing to vmcs12. This
is why we first make a copy of vmcs01 in memory (vmcs01_fields) and then
read that memory copy while writing to vmcs12.

Signed-off-by: Nadav Har'El <n...@il.ibm.com>
---
 arch/x86/kvm/vmx.c |  409 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 409 insertions(+)

--- .before/arch/x86/kvm/vmx.c  2010-12-08 18:56:50.000000000 +0200
+++ .after/arch/x86/kvm/vmx.c   2010-12-08 18:56:50.000000000 +0200
@@ -805,6 +805,28 @@ static inline bool report_flexpriority(v
        return flexpriority_enabled;
 }
 
+static inline bool nested_cpu_has_vmx_tpr_shadow(struct kvm_vcpu *vcpu)
+{
+       return cpu_has_vmx_tpr_shadow() &&
+               get_vmcs12_fields(vcpu)->cpu_based_vm_exec_control &
+               CPU_BASED_TPR_SHADOW;
+}
+
+static inline bool nested_cpu_has_secondary_exec_ctrls(struct kvm_vcpu *vcpu)
+{
+       return cpu_has_secondary_exec_ctrls() &&
+               get_vmcs12_fields(vcpu)->cpu_based_vm_exec_control &
+               CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
+}
+
+static inline bool nested_vm_need_virtualize_apic_accesses(struct kvm_vcpu
+                                                          *vcpu)
+{
+       return nested_cpu_has_secondary_exec_ctrls(vcpu) &&
+               (get_vmcs12_fields(vcpu)->secondary_vm_exec_control &
+               SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
+}
+
 static int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
 {
        int i;
@@ -1253,6 +1275,37 @@ static void vmx_load_host_state(struct v
        preempt_enable();
 }
 
+int load_vmcs_host_state(struct vmcs_fields *src)
+{
+       vmcs_write16(HOST_ES_SELECTOR, src->host_es_selector);
+       vmcs_write16(HOST_CS_SELECTOR, src->host_cs_selector);
+       vmcs_write16(HOST_SS_SELECTOR, src->host_ss_selector);
+       vmcs_write16(HOST_DS_SELECTOR, src->host_ds_selector);
+       vmcs_write16(HOST_FS_SELECTOR, src->host_fs_selector);
+       vmcs_write16(HOST_GS_SELECTOR, src->host_gs_selector);
+       vmcs_write16(HOST_TR_SELECTOR, src->host_tr_selector);
+
+       if (vmcs_config.vmexit_ctrl & VM_EXIT_LOAD_IA32_PAT)
+               vmcs_write64(HOST_IA32_PAT, src->host_ia32_pat);
+
+       vmcs_write32(HOST_IA32_SYSENTER_CS, src->host_ia32_sysenter_cs);
+
+       vmcs_writel(HOST_CR0, src->host_cr0);
+       vmcs_writel(HOST_CR3, src->host_cr3);
+       vmcs_writel(HOST_CR4, src->host_cr4);
+       vmcs_writel(HOST_FS_BASE, src->host_fs_base);
+       vmcs_writel(HOST_GS_BASE, src->host_gs_base);
+       vmcs_writel(HOST_TR_BASE, src->host_tr_base);
+       vmcs_writel(HOST_GDTR_BASE, src->host_gdtr_base);
+       vmcs_writel(HOST_IDTR_BASE, src->host_idtr_base);
+       vmcs_writel(HOST_RSP, src->host_rsp);
+       vmcs_writel(HOST_RIP, src->host_rip);
+       vmcs_writel(HOST_IA32_SYSENTER_ESP, src->host_ia32_sysenter_esp);
+       vmcs_writel(HOST_IA32_SYSENTER_EIP, src->host_ia32_sysenter_eip);
+
+       return 0;
+}
+
 /*
  * Switches to specified vcpu, until a matching vcpu_put(), but assumes
  * vcpu mutex is already taken.
@@ -5365,6 +5418,362 @@ static void vmx_set_supported_cpuid(u32 
                entry->ecx |= bit(X86_FEATURE_VMX);
 }
 
+/*
+ * Make a copy of the current VMCS to ordinary memory. This is needed because
+ * in VMX you cannot read and write to two VMCS at the same time, so when we
+ * want to do this (in prepare_vmcs02, which needs to read from vmcs01 while
+ * preparing vmcs02), we need to first save a copy of one VMCS's fields in
+ * memory, and then use that copy.
+ */
+void save_vmcs(struct vmcs_fields *dst)
+{
+       dst->guest_es_selector = vmcs_read16(GUEST_ES_SELECTOR);
+       dst->guest_cs_selector = vmcs_read16(GUEST_CS_SELECTOR);
+       dst->guest_ss_selector = vmcs_read16(GUEST_SS_SELECTOR);
+       dst->guest_ds_selector = vmcs_read16(GUEST_DS_SELECTOR);
+       dst->guest_fs_selector = vmcs_read16(GUEST_FS_SELECTOR);
+       dst->guest_gs_selector = vmcs_read16(GUEST_GS_SELECTOR);
+       dst->guest_ldtr_selector = vmcs_read16(GUEST_LDTR_SELECTOR);
+       dst->guest_tr_selector = vmcs_read16(GUEST_TR_SELECTOR);
+       dst->host_es_selector = vmcs_read16(HOST_ES_SELECTOR);
+       dst->host_cs_selector = vmcs_read16(HOST_CS_SELECTOR);
+       dst->host_ss_selector = vmcs_read16(HOST_SS_SELECTOR);
+       dst->host_ds_selector = vmcs_read16(HOST_DS_SELECTOR);
+       dst->host_fs_selector = vmcs_read16(HOST_FS_SELECTOR);
+       dst->host_gs_selector = vmcs_read16(HOST_GS_SELECTOR);
+       dst->host_tr_selector = vmcs_read16(HOST_TR_SELECTOR);
+       dst->io_bitmap_a = vmcs_read64(IO_BITMAP_A);
+       dst->io_bitmap_b = vmcs_read64(IO_BITMAP_B);
+       if (cpu_has_vmx_msr_bitmap())
+               dst->msr_bitmap = vmcs_read64(MSR_BITMAP);
+       dst->tsc_offset = vmcs_read64(TSC_OFFSET);
+       dst->virtual_apic_page_addr = vmcs_read64(VIRTUAL_APIC_PAGE_ADDR);
+       dst->apic_access_addr = vmcs_read64(APIC_ACCESS_ADDR);
+       dst->guest_physical_address = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
+       dst->vmcs_link_pointer = vmcs_read64(VMCS_LINK_POINTER);
+       dst->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
+       if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
+               dst->guest_ia32_pat = vmcs_read64(GUEST_IA32_PAT);
+       if (enable_ept) {
+               /* shadow pages tables on EPT */
+               dst->ept_pointer = vmcs_read64(EPT_POINTER);
+               dst->guest_pdptr0 = vmcs_read64(GUEST_PDPTR0);
+               dst->guest_pdptr1 = vmcs_read64(GUEST_PDPTR1);
+               dst->guest_pdptr2 = vmcs_read64(GUEST_PDPTR2);
+               dst->guest_pdptr3 = vmcs_read64(GUEST_PDPTR3);
+       }
+       dst->pin_based_vm_exec_control = vmcs_read32(PIN_BASED_VM_EXEC_CONTROL);
+       dst->cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
+       dst->exception_bitmap = vmcs_read32(EXCEPTION_BITMAP);
+       dst->page_fault_error_code_mask =
+               vmcs_read32(PAGE_FAULT_ERROR_CODE_MASK);
+       dst->page_fault_error_code_match =
+               vmcs_read32(PAGE_FAULT_ERROR_CODE_MATCH);
+       dst->cr3_target_count = vmcs_read32(CR3_TARGET_COUNT);
+       dst->vm_exit_controls = vmcs_read32(VM_EXIT_CONTROLS);
+       dst->vm_entry_controls = vmcs_read32(VM_ENTRY_CONTROLS);
+       dst->vm_entry_intr_info_field = vmcs_read32(VM_ENTRY_INTR_INFO_FIELD);
+       dst->vm_entry_exception_error_code =
+               vmcs_read32(VM_ENTRY_EXCEPTION_ERROR_CODE);
+       dst->vm_entry_instruction_len = vmcs_read32(VM_ENTRY_INSTRUCTION_LEN);
+       dst->tpr_threshold = vmcs_read32(TPR_THRESHOLD);
+       dst->secondary_vm_exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
+       if (enable_vpid && dst->secondary_vm_exec_control &
+           SECONDARY_EXEC_ENABLE_VPID)
+               dst->virtual_processor_id = vmcs_read16(VIRTUAL_PROCESSOR_ID);
+       dst->vm_instruction_error = vmcs_read32(VM_INSTRUCTION_ERROR);
+       dst->vm_exit_reason  = vmcs_read32(VM_EXIT_REASON);
+       dst->vm_exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
+       dst->vm_exit_intr_error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE);
+       dst->idt_vectoring_info_field = vmcs_read32(IDT_VECTORING_INFO_FIELD);
+       dst->idt_vectoring_error_code = vmcs_read32(IDT_VECTORING_ERROR_CODE);
+       dst->vm_exit_instruction_len = vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+       dst->vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+       dst->guest_es_limit = vmcs_read32(GUEST_ES_LIMIT);
+       dst->guest_cs_limit = vmcs_read32(GUEST_CS_LIMIT);
+       dst->guest_ss_limit = vmcs_read32(GUEST_SS_LIMIT);
+       dst->guest_ds_limit = vmcs_read32(GUEST_DS_LIMIT);
+       dst->guest_fs_limit = vmcs_read32(GUEST_FS_LIMIT);
+       dst->guest_gs_limit = vmcs_read32(GUEST_GS_LIMIT);
+       dst->guest_ldtr_limit = vmcs_read32(GUEST_LDTR_LIMIT);
+       dst->guest_tr_limit = vmcs_read32(GUEST_TR_LIMIT);
+       dst->guest_gdtr_limit = vmcs_read32(GUEST_GDTR_LIMIT);
+       dst->guest_idtr_limit = vmcs_read32(GUEST_IDTR_LIMIT);
+       dst->guest_es_ar_bytes = vmcs_read32(GUEST_ES_AR_BYTES);
+       dst->guest_cs_ar_bytes = vmcs_read32(GUEST_CS_AR_BYTES);
+       dst->guest_ss_ar_bytes = vmcs_read32(GUEST_SS_AR_BYTES);
+       dst->guest_ds_ar_bytes = vmcs_read32(GUEST_DS_AR_BYTES);
+       dst->guest_fs_ar_bytes = vmcs_read32(GUEST_FS_AR_BYTES);
+       dst->guest_gs_ar_bytes = vmcs_read32(GUEST_GS_AR_BYTES);
+       dst->guest_ldtr_ar_bytes = vmcs_read32(GUEST_LDTR_AR_BYTES);
+       dst->guest_tr_ar_bytes = vmcs_read32(GUEST_TR_AR_BYTES);
+       dst->guest_interruptibility_info =
+               vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
+       dst->guest_activity_state = vmcs_read32(GUEST_ACTIVITY_STATE);
+       dst->guest_sysenter_cs = vmcs_read32(GUEST_SYSENTER_CS);
+       dst->host_ia32_sysenter_cs = vmcs_read32(HOST_IA32_SYSENTER_CS);
+       dst->cr0_guest_host_mask = vmcs_readl(CR0_GUEST_HOST_MASK);
+       dst->cr4_guest_host_mask = vmcs_readl(CR4_GUEST_HOST_MASK);
+       dst->cr0_read_shadow = vmcs_readl(CR0_READ_SHADOW);
+       dst->cr4_read_shadow = vmcs_readl(CR4_READ_SHADOW);
+       dst->cr3_target_value0 = vmcs_readl(CR3_TARGET_VALUE0);
+       dst->cr3_target_value1 = vmcs_readl(CR3_TARGET_VALUE1);
+       dst->cr3_target_value2 = vmcs_readl(CR3_TARGET_VALUE2);
+       dst->cr3_target_value3 = vmcs_readl(CR3_TARGET_VALUE3);
+       dst->exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
+       dst->guest_linear_address = vmcs_readl(GUEST_LINEAR_ADDRESS);
+       dst->guest_cr0 = vmcs_readl(GUEST_CR0);
+       dst->guest_cr3 = vmcs_readl(GUEST_CR3);
+       dst->guest_cr4 = vmcs_readl(GUEST_CR4);
+       dst->guest_es_base = vmcs_readl(GUEST_ES_BASE);
+       dst->guest_cs_base = vmcs_readl(GUEST_CS_BASE);
+       dst->guest_ss_base = vmcs_readl(GUEST_SS_BASE);
+       dst->guest_ds_base = vmcs_readl(GUEST_DS_BASE);
+       dst->guest_fs_base = vmcs_readl(GUEST_FS_BASE);
+       dst->guest_gs_base = vmcs_readl(GUEST_GS_BASE);
+       dst->guest_ldtr_base = vmcs_readl(GUEST_LDTR_BASE);
+       dst->guest_tr_base = vmcs_readl(GUEST_TR_BASE);
+       dst->guest_gdtr_base = vmcs_readl(GUEST_GDTR_BASE);
+       dst->guest_idtr_base = vmcs_readl(GUEST_IDTR_BASE);
+       dst->guest_dr7 = vmcs_readl(GUEST_DR7);
+       dst->guest_rsp = vmcs_readl(GUEST_RSP);
+       dst->guest_rip = vmcs_readl(GUEST_RIP);
+       dst->guest_rflags = vmcs_readl(GUEST_RFLAGS);
+       dst->guest_pending_dbg_exceptions =
+               vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS);
+       dst->guest_sysenter_esp = vmcs_readl(GUEST_SYSENTER_ESP);
+       dst->guest_sysenter_eip = vmcs_readl(GUEST_SYSENTER_EIP);
+       dst->host_cr0 = vmcs_readl(HOST_CR0);
+       dst->host_cr3 = vmcs_readl(HOST_CR3);
+       dst->host_cr4 = vmcs_readl(HOST_CR4);
+       dst->host_fs_base = vmcs_readl(HOST_FS_BASE);
+       dst->host_gs_base = vmcs_readl(HOST_GS_BASE);
+       dst->host_tr_base = vmcs_readl(HOST_TR_BASE);
+       dst->host_gdtr_base = vmcs_readl(HOST_GDTR_BASE);
+       dst->host_idtr_base = vmcs_readl(HOST_IDTR_BASE);
+       dst->host_ia32_sysenter_esp = vmcs_readl(HOST_IA32_SYSENTER_ESP);
+       dst->host_ia32_sysenter_eip = vmcs_readl(HOST_IA32_SYSENTER_EIP);
+       dst->host_rsp = vmcs_readl(HOST_RSP);
+       dst->host_rip = vmcs_readl(HOST_RIP);
+       if (vmcs_config.vmexit_ctrl & VM_EXIT_LOAD_IA32_PAT)
+               dst->host_ia32_pat = vmcs_read64(HOST_IA32_PAT);
+}
+
+/*
+ * prepare_vmcs02 is called in when the L1 guest hypervisor runs its nested
+ * L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it
+ * with L0's wishes for its guest (vmsc01), so we can run the L2 guest in a
+ * way that will both be appropriate to L1's requests, and our needs.
+ */
+int prepare_vmcs02(struct kvm_vcpu *vcpu,
+       struct vmcs_fields *vmcs12, struct vmcs_fields *vmcs01)
+{
+       u32 exec_control;
+
+       vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
+       vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
+       vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector);
+       vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector);
+       vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector);
+       vmcs_write16(GUEST_GS_SELECTOR, vmcs12->guest_gs_selector);
+       vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector);
+       vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector);
+
+       vmcs_write64(GUEST_IA32_DEBUGCTL, vmcs12->guest_ia32_debugctl);
+
+       if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
+               vmcs_write64(GUEST_IA32_PAT, vmcs12->guest_ia32_pat);
+
+       vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
+                    vmcs12->vm_entry_intr_info_field);
+       vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE,
+                    vmcs12->vm_entry_exception_error_code);
+       vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
+                    vmcs12->vm_entry_instruction_len);
+
+       vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit);
+       vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit);
+       vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit);
+       vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit);
+       vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit);
+       vmcs_write32(GUEST_GS_LIMIT, vmcs12->guest_gs_limit);
+       vmcs_write32(GUEST_LDTR_LIMIT, vmcs12->guest_ldtr_limit);
+       vmcs_write32(GUEST_TR_LIMIT, vmcs12->guest_tr_limit);
+       vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit);
+       vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit);
+       vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes);
+       vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes);
+       vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes);
+       vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes);
+       vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes);
+       vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes);
+       vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes);
+       vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes);
+       vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
+                    vmcs12->guest_interruptibility_info);
+       vmcs_write32(GUEST_ACTIVITY_STATE, vmcs12->guest_activity_state);
+       vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs);
+
+       vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base);
+       vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base);
+       vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base);
+       vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base);
+       vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base);
+       vmcs_writel(GUEST_GS_BASE, vmcs12->guest_gs_base);
+       vmcs_writel(GUEST_LDTR_BASE, vmcs12->guest_ldtr_base);
+       vmcs_writel(GUEST_TR_BASE, vmcs12->guest_tr_base);
+       vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base);
+       vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);
+       vmcs_writel(GUEST_DR7, vmcs12->guest_dr7);
+       vmcs_writel(GUEST_RSP, vmcs12->guest_rsp);
+       vmcs_writel(GUEST_RIP, vmcs12->guest_rip);
+       vmcs_writel(GUEST_RFLAGS, vmcs12->guest_rflags);
+       vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS,
+                   vmcs12->guest_pending_dbg_exceptions);
+       vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp);
+       vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip);
+
+       vmcs_write64(VMCS_LINK_POINTER, vmcs12->vmcs_link_pointer);
+       vmcs_write64(IO_BITMAP_A, vmcs01->io_bitmap_a);
+       vmcs_write64(IO_BITMAP_B, vmcs01->io_bitmap_b);
+       if (cpu_has_vmx_msr_bitmap())
+               vmcs_write64(MSR_BITMAP, vmcs01->msr_bitmap);
+
+       if (vmcs12->vm_entry_msr_load_count > 0 ||
+                       vmcs12->vm_exit_msr_load_count > 0 ||
+                       vmcs12->vm_exit_msr_store_count > 0) {
+               printk(KERN_WARNING
+                       "%s: VMCS MSR_{LOAD,STORE} unsupported\n", __func__);
+       }
+
+       if (nested_cpu_has_vmx_tpr_shadow(vcpu)) {
+               struct page *page =
+                       nested_get_page(vcpu, vmcs12->virtual_apic_page_addr);
+               if (!page)
+                       return 1;
+               vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, page_to_phys(page));
+               kvm_release_page_clean(page);
+       }
+
+       if (nested_vm_need_virtualize_apic_accesses(vcpu)) {
+               struct page *page =
+                       nested_get_page(vcpu, vmcs12->apic_access_addr);
+               if (!page)
+                       return 1;
+               vmcs_write64(APIC_ACCESS_ADDR, page_to_phys(page));
+               kvm_release_page_clean(page);
+       }
+
+       vmcs_write32(PIN_BASED_VM_EXEC_CONTROL,
+                    (vmcs01->pin_based_vm_exec_control |
+                     vmcs12->pin_based_vm_exec_control));
+
+
+       /*
+        * Whether page-faults are trapped is determined by a combination of
+        * 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
+        * If enable_ept, L0 doesn't care about page faults and we should
+        * set all of these to L1's desires. However, if !enable_ept, L0 does
+        * care about (at least some) page faults, and because it is not easy
+        * (if at all possible?) to merge L0 and L1's desires, we simply ask
+        * to exit on each and every L2 page fault. This is done by setting
+        * MASK=MATCH=0 and (see below) EB.PF=1.
+        * Note that below we don't need special code to set EB.PF beyond the
+        * "or"ing of the EB of vmcs01 and vmcs12, because when enable_ept,
+        * vmcs01's EB.PF is 0 so the "or" will take vmcs12's value, and when
+        * !enable_ept, EB.PF is 1, so the "or" will always be 1.
+        *
+        * A problem with this approach (when !enable_ept) is that L1 may be
+        * injected with more page faults than it asked for. This could have
+        * caused problems, but in practice existing hypervisors don't care.
+        * To fix this, we will need to emulate the PFEC checking (on the L1
+        * page tables), using walk_addr(), when injecting PFs to L1.
+        */
+       vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK,
+               enable_ept ? vmcs12->page_fault_error_code_mask : 0);
+       vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH,
+               enable_ept ? vmcs12->page_fault_error_code_match : 0);
+
+       if (cpu_has_secondary_exec_ctrls()) {
+               u32 exec_control = vmcs01->secondary_vm_exec_control;
+               if (nested_cpu_has_secondary_exec_ctrls(vcpu)) {
+                       exec_control |= vmcs12->secondary_vm_exec_control;
+                       if (!vm_need_virtualize_apic_accesses(vcpu->kvm) ||
+                           !nested_vm_need_virtualize_apic_accesses(vcpu))
+                               exec_control &=
+                               ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
+               }
+               vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
+       }
+
+       load_vmcs_host_state(vmcs01);
+
+       if (vm_need_tpr_shadow(vcpu->kvm) &&
+           nested_cpu_has_vmx_tpr_shadow(vcpu))
+               vmcs_write32(TPR_THRESHOLD, vmcs12->tpr_threshold);
+
+       exec_control = vmcs01->cpu_based_vm_exec_control;
+       exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
+       exec_control &= ~CPU_BASED_VIRTUAL_NMI_PENDING;
+       exec_control &= ~CPU_BASED_TPR_SHADOW;
+       exec_control |= vmcs12->cpu_based_vm_exec_control;
+       if (!vm_need_tpr_shadow(vcpu->kvm) ||
+           vmcs12->virtual_apic_page_addr == 0) {
+               exec_control &= ~CPU_BASED_TPR_SHADOW;
+#ifdef CONFIG_X86_64
+               exec_control |= CPU_BASED_CR8_STORE_EXITING |
+                       CPU_BASED_CR8_LOAD_EXITING;
+#endif
+       } else if (exec_control & CPU_BASED_TPR_SHADOW) {
+#ifdef CONFIG_X86_64
+               exec_control &= ~CPU_BASED_CR8_STORE_EXITING;
+               exec_control &= ~CPU_BASED_CR8_LOAD_EXITING;
+#endif
+       }
+       vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, exec_control);
+
+       /* EXCEPTION_BITMAP and CR0_GUEST_HOST_MASK should basically be the
+        * bitwise-or of what L1 wants to trap for L2, and what we want to
+        * trap. However, vmx_fpu_activate/deactivate may have happened after
+        * we saved vmcs01, so we shouldn't trust its TS and NM_VECTOR bits
+        * and need to base them again on fpu_active. Note that CR0.TS also
+        * needs updating - we do this after this function returns (in
+        * nested_vmx_run).
+        */
+       vmcs_write32(EXCEPTION_BITMAP,
+                    ((vmcs01->exception_bitmap&~(1u<<NM_VECTOR)) |
+                     (vcpu->fpu_active ? 0 : (1u<<NM_VECTOR)) |
+                     vmcs12->exception_bitmap));
+       vmcs_writel(CR0_GUEST_HOST_MASK, vmcs12->cr0_guest_host_mask |
+                       (vcpu->fpu_active ? 0 : X86_CR0_TS));
+       vcpu->arch.cr0_guest_owned_bits = ~(vmcs12->cr0_guest_host_mask |
+                       (vcpu->fpu_active ? 0 : X86_CR0_TS));
+
+       vmcs_write32(VM_EXIT_CONTROLS,
+                    (vmcs01->vm_exit_controls &
+                       (~(VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT)))
+                      | vmcs12->vm_exit_controls);
+
+       vmcs_write32(VM_ENTRY_CONTROLS,
+                    (vmcs01->vm_entry_controls &
+                       (~(VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_IA32E_MODE)))
+                     | vmcs12->vm_entry_controls);
+
+       vmcs_writel(CR4_GUEST_HOST_MASK,
+                   (vmcs01->cr4_guest_host_mask |
+                    vmcs12->cr4_guest_host_mask));
+       vcpu->arch.cr4_guest_owned_bits = ~(vmcs01->cr4_guest_host_mask |
+               vmcs12->cr4_guest_host_mask);
+
+       vmcs_write64(TSC_OFFSET, vmcs01->tsc_offset + vmcs12->tsc_offset);
+
+       if (enable_ept) {
+               /* shadow page tables on EPT */
+               vmcs_write64(EPT_POINTER, vmcs01->ept_pointer);
+       }
+       return 0;
+}
+
 static struct kvm_x86_ops vmx_x86_ops = {
        .cpu_has_kvm_support = cpu_has_kvm_support,
        .disabled_by_bios = vmx_disabled_by_bios,
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to