Commit 2e4c0661 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Use MMU's role to compute PKRU bitmask 



Use the MMU's role to calculate the Protection Keys (Restrict Userspace)
bitmask instead of pulling bits from current vCPU state.  For some flows,
the vCPU state may not be correct (or relevant), e.g. EPT doesn't
interact with PKRU.  Case in point, the "ept" param simply disappears.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210622175739.3610207-34-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c596f147

arch/x86/kvm/mmu/mmu.c

+7 −14
Original line number Diff line number Diff line
@@ -4460,24 +4460,17 @@ static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 
* away both AD and WD.  For all reads or if the last condition holds, WD

* only will be masked away.

*/

static void update_pkru_bitmask(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,

				bool ept)

static void update_pkru_bitmask(struct kvm_mmu *mmu)

{

	unsigned bit;

	bool wp;



	if (ept) {

	if (!is_cr4_pke(mmu)) {

		mmu->pkru_mask = 0;

		return;

	}



	/* PKEY is enabled only if CR4.PKE and EFER.LMA are both set. */

	if (!kvm_read_cr4_bits(vcpu, X86_CR4_PKE) || !is_long_mode(vcpu)) {

		mmu->pkru_mask = 0;

		return;

	}



	wp = is_write_protection(vcpu);

	wp = is_cr0_wp(mmu);



	for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) {

		unsigned pfec, pkey_bits;
@@ -4672,7 +4665,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) 
	}



	update_permission_bitmask(context, false);

	update_pkru_bitmask(vcpu, context, false);

	update_pkru_bitmask(context);

	update_last_nonleaf_level(vcpu, context);

	reset_tdp_shadow_zero_bits_mask(vcpu, context);

}
@@ -4730,7 +4723,7 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *conte 
	if (____is_cr0_pg(regs)) {

		reset_rsvds_bits_mask(vcpu, context);

		update_permission_bitmask(context, false);

		update_pkru_bitmask(vcpu, context, false);

		update_pkru_bitmask(context);

		update_last_nonleaf_level(vcpu, context);

	}

	context->shadow_root_level = new_role.base.level;
@@ -4838,8 +4831,8 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 
	context->direct_map = false;



	update_permission_bitmask(context, true);

	update_pkru_bitmask(vcpu, context, true);

	update_last_nonleaf_level(vcpu, context);

	update_pkru_bitmask(context);

	reset_rsvds_bits_mask_ept(vcpu, context, execonly);

	reset_ept_shadow_zero_bits_mask(vcpu, context, execonly);

}
@@ -4935,7 +4928,7 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu) 
	}



	update_permission_bitmask(g_context, false);

	update_pkru_bitmask(vcpu, g_context, false);

	update_pkru_bitmask(g_context);

	update_last_nonleaf_level(vcpu, g_context);

}