Commit a8ac864a authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
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KVM: x86: Add helper to consolidate "raw" reserved GPA mask calculations 



Add a helper to generate the mask of reserved GPA bits _without_ any
adjustments for repurposed bits, and use it to replace a variety of
open coded variants in the MTRR and APIC_BASE flows.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210204000117.3303214-11-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6f8e65a6

arch/x86/kvm/cpuid.c

+11 −1
Original line number Diff line number Diff line
@@ -173,7 +173,7 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) 
	kvm_update_pv_runtime(vcpu);



	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);

	vcpu->arch.reserved_gpa_bits = rsvd_bits(cpuid_maxphyaddr(vcpu), 63);

	vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu);



	kvm_pmu_refresh(vcpu);

	vcpu->arch.cr4_guest_rsvd_bits =
@@ -227,6 +227,16 @@ int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 
	return 36;

}



/*

 * This "raw" version returns the reserved GPA bits without any adjustments for

 * encryption technologies that usurp bits.  The raw mask should be used if and

 * only if hardware does _not_ strip the usurped bits, e.g. in virtual MTRRs.

 */

u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu)

{

	return rsvd_bits(cpuid_maxphyaddr(vcpu), 63);

}



/* when an old userspace process fills a new kernel module */

int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,

			     struct kvm_cpuid *cpuid,

arch/x86/kvm/cpuid.h

+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 
	       u32 *ecx, u32 *edx, bool exact_only);



int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);

u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu);



static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)

{

arch/x86/kvm/mtrr.c

+6 −6
Original line number Diff line number Diff line
@@ -75,7 +75,7 @@ bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data) 
	/* variable MTRRs */

	WARN_ON(!(msr >= 0x200 && msr < 0x200 + 2 * KVM_NR_VAR_MTRR));



	mask = (~0ULL) << cpuid_maxphyaddr(vcpu);

	mask = kvm_vcpu_reserved_gpa_bits_raw(vcpu);

	if ((msr & 1) == 0) {

		/* MTRR base */

		if (!valid_mtrr_type(data & 0xff))
@@ -351,14 +351,14 @@ static void set_var_mtrr_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data) 
	if (var_mtrr_range_is_valid(cur))

		list_del(&mtrr_state->var_ranges[index].node);



	/* Extend the mask with all 1 bits to the left, since those

	 * bits must implicitly be 0.  The bits are then cleared

	 * when reading them.

	/*

	 * Set all illegal GPA bits in the mask, since those bits must

	 * implicitly be 0.  The bits are then cleared when reading them.

	 */

	if (!is_mtrr_mask)

		cur->base = data;

	else

		cur->mask = data | (-1LL << cpuid_maxphyaddr(vcpu));

		cur->mask = data | kvm_vcpu_reserved_gpa_bits_raw(vcpu);



	/* add it to the list if it's enabled. */

	if (var_mtrr_range_is_valid(cur)) {
@@ -426,7 +426,7 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) 
		else

			*pdata = vcpu->arch.mtrr_state.var_ranges[index].mask;



		*pdata &= (1ULL << cpuid_maxphyaddr(vcpu)) - 1;

		*pdata &= ~kvm_vcpu_reserved_gpa_bits_raw(vcpu);

	}



	return 0;

arch/x86/kvm/x86.c

+2 −2
Original line number Diff line number Diff line
@@ -407,7 +407,7 @@ int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 
{

	enum lapic_mode old_mode = kvm_get_apic_mode(vcpu);

	enum lapic_mode new_mode = kvm_apic_mode(msr_info->data);

	u64 reserved_bits = ((~0ULL) << cpuid_maxphyaddr(vcpu)) | 0x2ff |

	u64 reserved_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu) | 0x2ff |

		(guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE);



	if ((msr_info->data & reserved_bits) != 0 || new_mode == LAPIC_MODE_INVALID)
@@ -10078,7 +10078,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) 
	fx_init(vcpu);



	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);

	vcpu->arch.reserved_gpa_bits = rsvd_bits(cpuid_maxphyaddr(vcpu), 63);

	vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu);



	vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;