x86: Make the GDT remapping read-only on 64-bit

[mirror_ubuntu-jammy-kernel.git] / arch / x86 / kvm / vmx.c

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 98e82ee1e6996671f912a152dec5367baea45b80..596a76d82b11efc8d50f8f5394731ab42209d447 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -935,7 +935,6 @@ static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
  * when a CPU is brought down, and we need to VMCLEAR all VMCSs loaded on it.
  */
 static DEFINE_PER_CPU(struct list_head, loaded_vmcss_on_cpu);
-static DEFINE_PER_CPU(struct desc_ptr, host_gdt);
 
 /*
  * We maintian a per-CPU linked-list of vCPU, so in wakeup_handler() we
@@ -2052,14 +2051,13 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
  */
 static unsigned long segment_base(u16 selector)
 {
-       struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
        struct desc_struct *table;
        unsigned long v;
 
        if (!(selector & ~SEGMENT_RPL_MASK))
                return 0;
 
-       table = (struct desc_struct *)gdt->address;
+       table = get_current_gdt_ro();
 
        if ((selector & SEGMENT_TI_MASK) == SEGMENT_LDT) {
                u16 ldt_selector = kvm_read_ldt();
@@ -2164,7 +2162,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx)
 #endif
        if (vmx->host_state.msr_host_bndcfgs)
                wrmsrl(MSR_IA32_BNDCFGS, vmx->host_state.msr_host_bndcfgs);
-       load_gdt(this_cpu_ptr(&host_gdt));
+       load_fixmap_gdt(raw_smp_processor_id());
 }
 
 static void vmx_load_host_state(struct vcpu_vmx *vmx)
@@ -2266,7 +2264,7 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
        }
 
        if (!already_loaded) {
-               struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
+               unsigned long gdt = get_current_gdt_ro_vaddr();
                unsigned long sysenter_esp;
 
                kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
@@ -2277,7 +2275,7 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
                 */
                vmcs_writel(HOST_TR_BASE,
                            (unsigned long)this_cpu_ptr(&cpu_tss));
-               vmcs_writel(HOST_GDTR_BASE, gdt->address);
+               vmcs_writel(HOST_GDTR_BASE, gdt);   /* 22.2.4 */
 
                /*
                 * VM exits change the host TR limit to 0x67 after a VM
@@ -3465,8 +3463,6 @@ static int hardware_enable(void)
                ept_sync_global();
        }
 
-       native_store_gdt(this_cpu_ptr(&host_gdt));
-
        return 0;
 }