[PATCH] KVM: VMX: drop I/O permission bitmaps

[Quan Xu]

From: Quan Xu <quan....@gmail.com>

Since KVM removes the only I/O port 0x80 bypass on Intel hosts,
clear CPU_BASED_USE_IO_BITMAPS and set CPU_BASED_UNCOND_IO_EXITING
bit. Then these I/O permission bitmaps are not used at all, so
drop I/O permission bitmaps.

Signed-off-by: Jim Mattson <jmatt...@google.com>
Signed-off-by: Radim Krčmář <rkrc...@redhat.com>
Signed-off-by: Quan Xu <quan....@gmail.com>
---
 arch/x86/kvm/vmx.c |   17 +----------------
 1 files changed, 1 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2fd9a8c..3e4f760 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -771,8 +771,6 @@ enum segment_cache_field {
        FIELD(HOST_FS_SELECTOR, host_fs_selector),
        FIELD(HOST_GS_SELECTOR, host_gs_selector),
        FIELD(HOST_TR_SELECTOR, host_tr_selector),
-       FIELD64(IO_BITMAP_A, io_bitmap_a),
-       FIELD64(IO_BITMAP_B, io_bitmap_b),
        FIELD64(MSR_BITMAP, msr_bitmap),
        FIELD64(VM_EXIT_MSR_STORE_ADDR, vm_exit_msr_store_addr),
        FIELD64(VM_EXIT_MSR_LOAD_ADDR, vm_exit_msr_load_addr),
@@ -943,8 +941,6 @@ static bool nested_vmx_is_page_fault_vmexit(struct vmcs12 
*vmcs12,
 static DEFINE_PER_CPU(spinlock_t, blocked_vcpu_on_cpu_lock);
 
 enum {
-       VMX_IO_BITMAP_A,
-       VMX_IO_BITMAP_B,
        VMX_MSR_BITMAP_LEGACY,
        VMX_MSR_BITMAP_LONGMODE,
        VMX_MSR_BITMAP_LEGACY_X2APIC_APICV,
@@ -958,8 +954,6 @@ enum {
 
 static unsigned long *vmx_bitmap[VMX_BITMAP_NR];
 
-#define vmx_io_bitmap_a                      (vmx_bitmap[VMX_IO_BITMAP_A])
-#define vmx_io_bitmap_b                      (vmx_bitmap[VMX_IO_BITMAP_B])
 #define vmx_msr_bitmap_legacy                
(vmx_bitmap[VMX_MSR_BITMAP_LEGACY])
 #define vmx_msr_bitmap_longmode              
(vmx_bitmap[VMX_MSR_BITMAP_LONGMODE])
 #define vmx_msr_bitmap_legacy_x2apic_apicv   
(vmx_bitmap[VMX_MSR_BITMAP_LEGACY_X2APIC_APICV])
@@ -3632,7 +3626,7 @@ static __init int setup_vmcs_config(struct vmcs_config 
*vmcs_conf)
 #endif
              CPU_BASED_CR3_LOAD_EXITING |
              CPU_BASED_CR3_STORE_EXITING |
-             CPU_BASED_USE_IO_BITMAPS |
+             CPU_BASED_UNCOND_IO_EXITING |
              CPU_BASED_MOV_DR_EXITING |
              CPU_BASED_USE_TSC_OFFSETING |
              CPU_BASED_INVLPG_EXITING |
@@ -5445,10 +5439,6 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
 #endif
        int i;
 
-       /* I/O */
-       vmcs_write64(IO_BITMAP_A, __pa(vmx_io_bitmap_a));
-       vmcs_write64(IO_BITMAP_B, __pa(vmx_io_bitmap_b));
-
        if (enable_shadow_vmcs) {
                vmcs_write64(VMREAD_BITMAP, __pa(vmx_vmread_bitmap));
                vmcs_write64(VMWRITE_BITMAP, __pa(vmx_vmwrite_bitmap));
@@ -6751,14 +6741,9 @@ static __init int hardware_setup(void)
                        goto out;
        }
 
-       vmx_io_bitmap_b = (unsigned long *)__get_free_page(GFP_KERNEL);
        memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE);
        memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE);
 
-       memset(vmx_io_bitmap_a, 0xff, PAGE_SIZE);
-
-       memset(vmx_io_bitmap_b, 0xff, PAGE_SIZE);
-
        memset(vmx_msr_bitmap_legacy, 0xff, PAGE_SIZE);
        memset(vmx_msr_bitmap_longmode, 0xff, PAGE_SIZE);
 
-- 
1.7.1