Commit e7581cac authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: x86: simplify is_mmio_spte 



We can simply look at bits 52-53 to identify MMIO entries in KVM's page
tables.  Therefore, there is no need to pass a mask to kvm_mmu_set_mmio_spte_mask.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f4cfcd2d

arch/x86/kvm/mmu.h

+1 −1
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ static inline u64 rsvd_bits(int s, int e) 
	return ((1ULL << (e - s + 1)) - 1) << s;

}



void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value, u64 access_mask);

void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 access_mask);



void

reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context);

arch/x86/kvm/mmu/mmu.c

+3 −7
Original line number Diff line number Diff line
@@ -244,7 +244,6 @@ static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */ 
static u64 __read_mostly shadow_user_mask;

static u64 __read_mostly shadow_accessed_mask;

static u64 __read_mostly shadow_dirty_mask;

static u64 __read_mostly shadow_mmio_mask;

static u64 __read_mostly shadow_mmio_value;

static u64 __read_mostly shadow_mmio_access_mask;

static u64 __read_mostly shadow_present_mask;
@@ -331,21 +330,19 @@ static void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 
	kvm_flush_remote_tlbs_with_range(kvm, &range);

}



void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value, u64 access_mask)

void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 access_mask)

{

	BUG_ON((u64)(unsigned)access_mask != access_mask);

	BUG_ON((mmio_mask & mmio_value) != mmio_value);

	WARN_ON(mmio_value & (shadow_nonpresent_or_rsvd_mask << shadow_nonpresent_or_rsvd_mask_len));

	WARN_ON(mmio_value & shadow_nonpresent_or_rsvd_lower_gfn_mask);

	shadow_mmio_value = mmio_value | SPTE_MMIO_MASK;

	shadow_mmio_mask = mmio_mask | SPTE_SPECIAL_MASK;

	shadow_mmio_access_mask = access_mask;

}

EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask);



static bool is_mmio_spte(u64 spte)

{

	return (spte & shadow_mmio_mask) == shadow_mmio_value;

	return (spte & SPTE_SPECIAL_MASK) == SPTE_MMIO_MASK;

}



static inline bool sp_ad_disabled(struct kvm_mmu_page *sp)
@@ -568,7 +565,6 @@ static void kvm_mmu_reset_all_pte_masks(void) 
	shadow_dirty_mask = 0;

	shadow_nx_mask = 0;

	shadow_x_mask = 0;

	shadow_mmio_mask = 0;

	shadow_present_mask = 0;

	shadow_acc_track_mask = 0;
@@ -6154,7 +6150,7 @@ static void kvm_set_mmio_spte_mask(void) 
	else

		mask = 0;



	kvm_mmu_set_mmio_spte_mask(mask, mask, ACC_WRITE_MASK | ACC_USER_MASK);

	kvm_mmu_set_mmio_spte_mask(mask, ACC_WRITE_MASK | ACC_USER_MASK);

}



static bool get_nx_auto_mode(void)

arch/x86/kvm/svm/svm.c

+1 −1
Original line number Diff line number Diff line
@@ -780,7 +780,7 @@ static __init void svm_adjust_mmio_mask(void) 
	 */

	mask = (mask_bit < 52) ? rsvd_bits(mask_bit, 51) | PT_PRESENT_MASK : 0;



	kvm_mmu_set_mmio_spte_mask(mask, mask, PT_WRITABLE_MASK | PT_USER_MASK);

	kvm_mmu_set_mmio_spte_mask(mask, PT_WRITABLE_MASK | PT_USER_MASK);

}



static void svm_hardware_teardown(void)

arch/x86/kvm/vmx/vmx.c

+1 −2
Original line number Diff line number Diff line
@@ -4147,8 +4147,7 @@ static void ept_set_mmio_spte_mask(void) 
	 * EPT Misconfigurations can be generated if the value of bits 2:0

	 * of an EPT paging-structure entry is 110b (write/execute).

	 */

	kvm_mmu_set_mmio_spte_mask(VMX_EPT_RWX_MASK,

				   VMX_EPT_MISCONFIG_WX_VALUE, 0);

	kvm_mmu_set_mmio_spte_mask(VMX_EPT_MISCONFIG_WX_VALUE, 0);

}



#define VMX_XSS_EXIT_BITMAP 0