Commit 9ae38b4f authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: x86: Add helper to get variable MTRR range from MSR index 



Add a helper to dedup the logic for retrieving a variable MTRR range
structure given a variable MTRR MSR index.

No functional change intended.

Reviewed-by: default avatarKai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230511233351.635053-5-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent ebda79e5

arch/x86/kvm/mtrr.c

+13 −10
Original line number Diff line number Diff line
@@ -31,6 +31,14 @@ static bool is_mtrr_base_msr(unsigned int msr) 
	return !(msr & 0x1);

}



static struct kvm_mtrr_range *var_mtrr_msr_to_range(struct kvm_vcpu *vcpu,

						    unsigned int msr)

{

	int index = (msr - 0x200) / 2;



	return &vcpu->arch.mtrr_state.var_ranges[index];

}



static bool msr_mtrr_valid(unsigned msr)

{

	switch (msr) {
@@ -314,7 +322,6 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr) 
{

	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;

	gfn_t start, end;

	int index;



	if (msr == MSR_IA32_CR_PAT || !tdp_enabled ||

	      !kvm_arch_has_noncoherent_dma(vcpu->kvm))
@@ -332,8 +339,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr) 
		end = ~0ULL;

	} else {

		/* variable range MTRRs. */

		index = (msr - 0x200) / 2;

		var_mtrr_range(&mtrr_state->var_ranges[index], &start, &end);

		var_mtrr_range(var_mtrr_msr_to_range(vcpu, msr), &start, &end);

	}



	kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end));
@@ -348,14 +354,12 @@ static void set_var_mtrr_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data) 
{

	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;

	struct kvm_mtrr_range *tmp, *cur;

	int index;



	index = (msr - 0x200) / 2;

	cur = &mtrr_state->var_ranges[index];

	cur = var_mtrr_msr_to_range(vcpu, msr);



	/* remove the entry if it's in the list. */

	if (var_mtrr_range_is_valid(cur))

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

		list_del(&cur->node);



	/*

	 * Set all illegal GPA bits in the mask, since those bits must
@@ -423,11 +427,10 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) 
	else if (msr == MSR_IA32_CR_PAT)

		*pdata = vcpu->arch.pat;

	else {	/* Variable MTRRs */

		index = (msr - 0x200) / 2;

		if (is_mtrr_base_msr(msr))

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

			*pdata = var_mtrr_msr_to_range(vcpu, msr)->base;

		else

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

			*pdata = var_mtrr_msr_to_range(vcpu, msr)->mask;



		*pdata &= ~kvm_vcpu_reserved_gpa_bits_raw(vcpu);

	}