KVM: x86: Add helpers to query individual CR0/CR4 bits

Add helpers to check if a specific CR0/CR4 bit is set to avoid a plethora
of implicit casts from the "unsigned long" return of kvm_read_cr*_bits(),
and to make each caller's intent more obvious.

Defer converting helpers that do truly ugly casts from "unsigned long" to
"int", e.g. is_pse(), to a future commit so that their conversion is more
isolated.

Opportunistically drop the superfluous pcid_enabled from kvm_set_cr3();
the local variable is used only once, immediately after its declaration.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/r/20230322045824.22970-2-binbin.wu@linux.intel.com
[sean: move "obvious" conversions to this commit, massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 10 insertions, 12 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8a66ac7a4878..3fab192862d4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -841,7 +841,7 @@ bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl)
 
 bool kvm_require_dr(struct kvm_vcpu *vcpu, int dr)
 {
-	if ((dr != 4 && dr != 5) || !kvm_read_cr4_bits(vcpu, X86_CR4_DE))
+	if ((dr != 4 && dr != 5) || !kvm_is_cr4_bit_set(vcpu, X86_CR4_DE))
 		return true;
 
 	kvm_queue_exception(vcpu, UD_VECTOR);
@@ -983,7 +983,7 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 		return 1;
 
 	if (!(cr0 & X86_CR0_PG) &&
-	    (is_64_bit_mode(vcpu) || kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE)))
+	    (is_64_bit_mode(vcpu) || kvm_is_cr4_bit_set(vcpu, X86_CR4_PCIDE)))
 		return 1;
 
 	static_call(kvm_x86_set_cr0)(vcpu, cr0);
@@ -1005,7 +1005,7 @@ void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu)
 	if (vcpu->arch.guest_state_protected)
 		return;
 
-	if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) {
+	if (kvm_is_cr4_bit_set(vcpu, X86_CR4_OSXSAVE)) {
 
 		if (vcpu->arch.xcr0 != host_xcr0)
 			xsetbv(XCR_XFEATURE_ENABLED_MASK, vcpu->arch.xcr0);
@@ -1019,7 +1019,7 @@ void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu)
 	if (static_cpu_has(X86_FEATURE_PKU) &&
 	    vcpu->arch.pkru != vcpu->arch.host_pkru &&
 	    ((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) ||
-	     kvm_read_cr4_bits(vcpu, X86_CR4_PKE)))
+	     kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE)))
 		write_pkru(vcpu->arch.pkru);
 #endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */
 }
@@ -1033,14 +1033,14 @@ void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu)
 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
 	if (static_cpu_has(X86_FEATURE_PKU) &&
 	    ((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) ||
-	     kvm_read_cr4_bits(vcpu, X86_CR4_PKE))) {
+	     kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE))) {
 		vcpu->arch.pkru = rdpkru();
 		if (vcpu->arch.pkru != vcpu->arch.host_pkru)
 			write_pkru(vcpu->arch.host_pkru);
 	}
 #endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */
 
-	if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) {
+	if (kvm_is_cr4_bit_set(vcpu, X86_CR4_OSXSAVE)) {
 
 		if (vcpu->arch.xcr0 != host_xcr0)
 			xsetbv(XCR_XFEATURE_ENABLED_MASK, host_xcr0);
@@ -1245,7 +1245,7 @@ static void kvm_invalidate_pcid(struct kvm_vcpu *vcpu, unsigned long pcid)
 	 * PCIDs for them are also 0, because MOV to CR3 always flushes the TLB
 	 * with PCIDE=0.
 	 */
-	if (!kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE))
+	if (!kvm_is_cr4_bit_set(vcpu, X86_CR4_PCIDE))
 		return;
 
 	for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++)
@@ -1260,9 +1260,7 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 	bool skip_tlb_flush = false;
 	unsigned long pcid = 0;
 #ifdef CONFIG_X86_64
-	bool pcid_enabled = kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE);
-
-	if (pcid_enabled) {
+	if (kvm_is_cr4_bit_set(vcpu, X86_CR4_PCIDE)) {
 		skip_tlb_flush = cr3 & X86_CR3_PCID_NOFLUSH;
 		cr3 &= ~X86_CR3_PCID_NOFLUSH;
 		pcid = cr3 & X86_CR3_PCID_MASK;
@@ -5051,7 +5049,7 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
 		return 0;
 	if (mce->status & MCI_STATUS_UC) {
 		if ((vcpu->arch.mcg_status & MCG_STATUS_MCIP) ||
-		    !kvm_read_cr4_bits(vcpu, X86_CR4_MCE)) {
+		    !kvm_is_cr4_bit_set(vcpu, X86_CR4_MCE)) {
 			kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
 			return 0;
 		}
@@ -13254,7 +13252,7 @@ int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned long type, gva_t gva)
 		return 1;
 	}
 
-	pcid_enabled = kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE);
+	pcid_enabled = kvm_is_cr4_bit_set(vcpu, X86_CR4_PCIDE);
 
 	switch (type) {
 	case INVPCID_TYPE_INDIV_ADDR: