On 12/10/2009 08:38 PM, [email protected] wrote:
From: Orit Wasserman<[email protected]>
---
arch/x86/kvm/vmx.c | 235 +++++++++++++++++++++++++++++++++++++++++++++++++++-
arch/x86/kvm/x86.c | 5 +-
arch/x86/kvm/x86.h | 3 +
3 files changed, 240 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2726a6c..a7ffd5e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -93,13 +93,39 @@ struct shared_msr_entry {
};
struct __attribute__ ((__packed__)) level_state {
+ /* Has the level1 guest done vmclear? */
+ bool vmclear;
+};
Suggest calling it launch_state and using an enum. We can have three
states: uninitialized, clear, and launched. Not sure if this is really
required by the spec.
Do we need vmclear in l1_state?
+struct __attribute__ ((__packed__)) nested_vmcs_page {
+ u32 revision_id;
+ u32 abort;
+ struct level_state l2_state;
+};
+
+struct nested_vmcs_list {
+ struct list_head list;
'link'
+ gpa_t vmcs_addr;
+ struct vmcs *l2_vmcs;
};
struct nested_vmx {
/* Has the level1 guest done vmxon? */
bool vmxon;
+ /* What is the location of the current vmcs l1 keeps for l2 */
+ gpa_t current_vmptr;
/* Level 1 state for switching to level 2 and back */
struct level_state *l1_state;
+ /* list of vmcs for each l2 guest created by l1 */
+ struct list_head l2_vmcs_list;
+ /* l2 page corresponding to the current vmcs set by l1 */
+ struct nested_vmcs_page *current_l2_page;
};
struct vcpu_vmx {
@@ -156,6 +182,76 @@ static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu
*vcpu)
return container_of(vcpu, struct vcpu_vmx, vcpu);
}
+static struct page *nested_get_page(struct kvm_vcpu *vcpu,
+ u64 vmcs_addr)
+{
+ struct page *vmcs_page = NULL;
+
+ down_read(¤t->mm->mmap_sem);
+ vmcs_page = gfn_to_page(vcpu->kvm, vmcs_addr>> PAGE_SHIFT);
+ up_read(¤t->mm->mmap_sem);
gfn_to_page() doesn't need mmap_sem (and may deadlock if you take it).
+
+ if (is_error_page(vmcs_page)) {
+ printk(KERN_ERR "%s error allocating page 0x%llx\n",
+ __func__, vmcs_addr);
+ kvm_release_page_clean(vmcs_page);
+ return NULL;
+ }
+
+ return vmcs_page;
+
+}
+
+static int nested_map_current(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ struct page *vmcs_page =
+ nested_get_page(vcpu, vmx->nested.current_vmptr);
+ struct nested_vmcs_page *mapped_page;
+
+ if (vmcs_page == NULL) {
+ printk(KERN_INFO "%s: failure in nested_get_page\n", __func__);
+ return 0;
+ }
+
+ if (vmx->nested.current_l2_page) {
+ printk(KERN_INFO "%s: shadow vmcs already mapped\n", __func__);
+ WARN_ON(1);
+ return 0;
+ }
+
+ mapped_page = kmap_atomic(vmcs_page, KM_USER0);
+
+ if (!mapped_page) {
+ printk(KERN_INFO "%s: error in kmap_atomic\n", __func__);
+ return 0;
+ }
kmap_atomic() can't fail.
+
+ vmx->nested.current_l2_page = mapped_page;
+
+ return 1;
+}
+
+static void nested_unmap_current(struct kvm_vcpu *vcpu)
+{
+ struct page *page;
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ if (!vmx->nested.current_l2_page) {
+ printk(KERN_INFO "Shadow vmcs already unmapped\n");
+ WARN_ON(1);
Use BUG_ON(), since this can't happen unless there's a bug.
+ return;
+ }
+
+ page = kmap_atomic_to_page(vmx->nested.current_l2_page);
+
+ kunmap_atomic(vmx->nested.current_l2_page, KM_USER0);
+
+ kvm_release_page_dirty(page);
+
+ vmx->nested.current_l2_page = NULL;
+}
+
static int init_rmode(struct kvm *kvm);
static u64 construct_eptp(unsigned long root_hpa);
@@ -1144,6 +1240,35 @@ static int nested_vmx_set_msr(struct kvm_vcpu *vcpu, u32
msr_index, u64 data)
return 0;
}
+static int read_guest_vmcs_gpa(struct kvm_vcpu *vcpu, gva_t gva, u64 *gentry)
+{
+ int r = 0;
+ uint size;
+
+ *gentry = 0;
+
+ if (is_long_mode(vcpu))
+ size = sizeof(u64);
+ else
+ size = sizeof(u32);
I think the gpa is always 64 bit, regardless of the current mode.
+
+ r = kvm_read_guest_virt(gva, gentry,
+ size, vcpu);
+ if (r) {
+ printk(KERN_ERR "%s cannot read guest vmcs addr %lx : %d\n",
+ __func__, vcpu->arch.regs[VCPU_REGS_RAX], r);
RAX may not be relevant. Just return, and the user can disassemble the
instructions and see for themselves.
+ return r;
+ }
+
+ if (!IS_ALIGNED(*gentry, PAGE_SIZE)) {
+ printk(KERN_DEBUG "%s addr %llx not aligned\n",
+ __func__, *gentry);
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * Decode the memory address (operand) of a vmx instruction according to Table
23-12/23-11
+ * For additional information regarding offset calculation see 3.7.5
+ */
+static gva_t get_vmx_mem_address(struct kvm_vcpu *vcpu,
+ unsigned long exit_qualification,
+ u32 vmx_instruction_info)
+{
+ int scaling = vmx_instruction_info& 3; /* bits 0:1
scaling */
+ int addr_size = (vmx_instruction_info>> 7)& 7; /* bits 7:9
address size, 0=16bit, 1=32bit, 2=64bit */
+ bool is_reg = vmx_instruction_info& (1u<< 10); /* bit 10
1=register operand, 0= memory */
+ int seg_reg = (vmx_instruction_info>> 15)& 7; /* bits
15:17 segment register */
+ int index_reg = (vmx_instruction_info>> 18)& 0xf; /* bits
18:21 index register */
+ bool index_is_valid = !(vmx_instruction_info& (1u<< 22)); /* bit 22
index register validity, 0=valid, 1=invalid */
+ int base_reg = (vmx_instruction_info>> 23)& 0xf; /* bits
23:26 index register */
+ bool base_is_valid = !(vmx_instruction_info& (1u<< 27)); /* bit 27
base register validity, 0=valid, 1=invalid */
+ gva_t addr;
+
+ if (is_reg)
+ return 0;
Should #UD.
+
+ switch (addr_size) {
+ case 1:
+ exit_qualification&= 0xffffffff; /* 32 high bits are undefied
according to the spec, page 23-7 */
+ break;
+ case 2:
+ break;
+ default:
+ return 0;
+ }
+
+ /* Addr = segment_base + offset */
+ /* offfset = Base + [Index * Scale] + Displacement, see Figure 3-11 */
+ addr = vmx_get_segment_base(vcpu, seg_reg);
+ if (base_is_valid)
+ addr += kvm_register_read(vcpu, base_reg);
+ if (index_is_valid)
+ addr += kvm_register_read(vcpu, index_reg)*scaling;
Shouldn't this be a shift?
Wish we had something like that for emulate.c.
+ addr += exit_qualification; /* exit qualification holds the
displacement, spec page 23-7 */
+
+ return addr;
+}
+
+static int handle_vmclear(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ struct level_state *l2_state;
+ gpa_t guest_vmcs_addr;
+ unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
+ u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+ gva_t vmcs_gva;
+
+ if (!nested_vmx_check_permission(vcpu))
+ return 1;
+
+ vmcs_gva = get_vmx_mem_address(vcpu, exit_qualification,
+ vmx_instruction_info);
I think you can let get_vmx_mem_address() do the vmread()s, simpler.
+
+ if (read_guest_vmcs_gpa(vcpu, vmcs_gva,&guest_vmcs_addr))
+ return 1;
+
+ vmx->nested.current_vmptr = guest_vmcs_addr;
+ if (!nested_map_current(vcpu))
+ return 1;
+
+ l2_state =&(to_vmx(vcpu)->nested.current_l2_page->l2_state);
+ l2_state->vmclear = 1;
+ nested_free_current_vmcs(vcpu);
Why free? Isn't the purpose of the list to keep those active?
+
+ vmx->nested.current_vmptr = -1ull;
+
+ nested_unmap_current(vcpu);
+
+ skip_emulated_instruction(vcpu);
+ clear_rflags_cf_zf(vcpu);
+
+ return 1;
+}
+
As usual, if you can split some of the infrastructure into separate
patches, it would help review.
--
error compiling committee.c: too many arguments to function
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