[PATCH v2 00/15] KVM: x86: VMX: Fix MSR namespacing

[PATCH v2 00/15] KVM: x86: VMX: Fix MSR namespacing

[Sean Christopherson]

This series attempts to clean up VMX's MSR namespacing, which is in
unimitigated disaster (keeping things PG).

There are a variety of ways VMX saves and restores guest MSRs, all with
unique properties and mechanisms, but with haphazard namespacing (assuming
there is any namespacing at all).  Some fun collisions:

  __find_msr_index(), find_msr_entry() and vmx_find_msr_index()

  vmx_set_guest_msr() and vmx_set_msr()

  structs vmx_msrs, vmx_msr_entry, shared_msr_entry, kvm_shared_msrs and
  kvm_shared_msrs_values

  vcpu_vmx fields guest_msrs, msr_autoload.guest and msr_autostore.guest

Probably the most infurating/confusing nomenclature is "index", which can
mean MSR's ECX index, index into one of several VMX arrays, or index into
a common x86 array.  __find_msr_index() even manages to mix at least three
different meanings in about as many lines of code.

The biggest change is to rename the "shared MSRs" mechanism to "user
return MSRs" (details in patch 1), most everything else is either derived
from that rename or is fairly straightforward cleanup.

No true functional changes, although the update_transition_efer() change
in patch 10 dances pretty close to being a functional change.

v2:
  - Rebased to kvm/queue, commit e1ba1a15af73 ("KVM: SVM: Enable INVPCID
    feature on AMD").

Sean Christopherson (15):
  KVM: x86: Rename "shared_msrs" to "user_return_msrs"
  KVM: VMX: Prepend "MAX_" to MSR array size defines
  KVM: VMX: Rename "vmx_find_msr_index" to "vmx_find_loadstore_msr_slot"
  KVM: VMX: Rename the "shared_msr_entry" struct to "vmx_uret_msr"
  KVM: VMX: Rename vcpu_vmx's "nmsrs" to "nr_uret_msrs"
  KVM: VMX: Rename vcpu_vmx's "save_nmsrs" to "nr_active_uret_msrs"
  KVM: VMX: Rename vcpu_vmx's "guest_msrs_ready" to
    "guest_uret_msrs_loaded"
  KVM: VMX: Rename "__find_msr_index" to "__vmx_find_uret_msr"
  KVM: VMX: Check guest support for RDTSCP before processing MSR_TSC_AUX
  KVM: VMX: Move uret MSR lookup into update_transition_efer()
  KVM: VMX: Add vmx_setup_uret_msr() to handle lookup and swap
  KVM: VMX: Rename "find_msr_entry" to "vmx_find_uret_msr"
  KVM: VMX: Rename "vmx_set_guest_msr" to "vmx_set_guest_uret_msr"
  KVM: VMX: Rename "vmx_msr_index" to "vmx_uret_msrs_list"
  KVM: VMX: Rename vmx_uret_msr's "index" to "slot"

 arch/x86/include/asm/kvm_host.h |   4 +-
 arch/x86/kvm/vmx/nested.c       |  22 ++--
 arch/x86/kvm/vmx/vmx.c          | 184 ++++++++++++++++----------------
 arch/x86/kvm/vmx/vmx.h          |  24 ++---
 arch/x86/kvm/x86.c              | 101 +++++++++---------
 5 files changed, 168 insertions(+), 167 deletions(-)

-- 
2.28.0

[PATCH v2 01/15] KVM: x86: Rename "shared_msrs" to "user_return_msrs"

[Sean Christopherson]

Rename the "shared_msrs" mechanism, which is used to defer restoring
MSRs that are only consumed when running in userspace, to a more banal
but less likely to be confusing "user_return_msrs".

The "shared" nomenclature is confusing as it's not obvious who is
sharing what, e.g. reasonable interpretations are that the guest value
is shared by vCPUs in a VM, or that the MSR value is shared/common to
guest and host, both of which are wrong.

"shared" is also misleading as the MSR value (in hardware) is not
guaranteed to be shared/reused between VMs (if that's indeed the correct
interpretation of the name), as the ability to share values between VMs
is simply a side effect (albiet a very nice side effect) of deferring
restoration of the host value until returning from userspace.

"user_return" avoids the above confusion by describing the mechanism
itself instead of its effects.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/include/asm/kvm_host.h |   4 +-
 arch/x86/kvm/vmx/vmx.c          |  11 ++--
 arch/x86/kvm/x86.c              | 101 +++++++++++++++++---------------
 3 files changed, 60 insertions(+), 56 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5303dbc5c9bc..2166df4536e4 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1612,8 +1612,8 @@ int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low,
 		    unsigned long ipi_bitmap_high, u32 min,
 		    unsigned long icr, int op_64_bit);
 
-void kvm_define_shared_msr(unsigned index, u32 msr);
-int kvm_set_shared_msr(unsigned index, u64 val, u64 mask);
+void kvm_define_user_return_msr(unsigned index, u32 msr);
+int kvm_set_user_return_msr(unsigned index, u64 val, u64 mask);
 
 u64 kvm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc);
 u64 kvm_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6f9a0c6d5dc5..ae7badc3b5bd 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -651,8 +651,7 @@ static int vmx_set_guest_msr(struct vcpu_vmx *vmx, struct shared_msr_entry *msr,
 	msr->data = data;
 	if (msr - vmx->guest_msrs < vmx->save_nmsrs) {
 		preempt_disable();
-		ret = kvm_set_shared_msr(msr->index, msr->data,
-					 msr->mask);
+		ret = kvm_set_user_return_msr(msr->index, msr->data, msr->mask);
 		preempt_enable();
 		if (ret)
 			msr->data = old_msr_data;
@@ -1144,9 +1143,9 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
 	if (!vmx->guest_msrs_ready) {
 		vmx->guest_msrs_ready = true;
 		for (i = 0; i < vmx->save_nmsrs; ++i)
-			kvm_set_shared_msr(vmx->guest_msrs[i].index,
-					   vmx->guest_msrs[i].data,
-					   vmx->guest_msrs[i].mask);
+			kvm_set_user_return_msr(vmx->guest_msrs[i].index,
+						vmx->guest_msrs[i].data,
+						vmx->guest_msrs[i].mask);
 
 	}
 
@@ -7922,7 +7921,7 @@ static __init int hardware_setup(void)
 	host_idt_base = dt.address;
 
 	for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i)
-		kvm_define_shared_msr(i, vmx_msr_index[i]);
+		kvm_define_user_return_msr(i, vmx_msr_index[i]);
 
 	if (setup_vmcs_config(&vmcs_config, &vmx_capability) < 0)
 		return -EIO;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 17f4995e80a7..d6cf4a294c1c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -162,24 +162,29 @@ module_param(force_emulation_prefix, bool, S_IRUGO);
 int __read_mostly pi_inject_timer = -1;
 module_param(pi_inject_timer, bint, S_IRUGO | S_IWUSR);
 
-#define KVM_NR_SHARED_MSRS 16
+/*
+ * Restoring the host value for MSRs that are only consumed when running in
+ * usermode, e.g. SYSCALL MSRs and TSC_AUX, can be deferred until the CPU
+ * returns to userspace, i.e. the kernel can run with the guest's value.
+ */
+#define KVM_MAX_NR_USER_RETURN_MSRS 16
 
-struct kvm_shared_msrs_global {
+struct kvm_user_return_msrs_global {
 	int nr;
-	u32 msrs[KVM_NR_SHARED_MSRS];
+	u32 msrs[KVM_MAX_NR_USER_RETURN_MSRS];
 };
 
-struct kvm_shared_msrs {
+struct kvm_user_return_msrs {
 	struct user_return_notifier urn;
 	bool registered;
-	struct kvm_shared_msr_values {
+	struct kvm_user_return_msr_values {
 		u64 host;
 		u64 curr;
-	} values[KVM_NR_SHARED_MSRS];
+	} values[KVM_MAX_NR_USER_RETURN_MSRS];
 };
 
-static struct kvm_shared_msrs_global __read_mostly shared_msrs_global;
-static struct kvm_shared_msrs __percpu *shared_msrs;
+static struct kvm_user_return_msrs_global __read_mostly user_return_msrs_global;
+static struct kvm_user_return_msrs __percpu *user_return_msrs;
 
 #define KVM_SUPPORTED_XCR0     (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \
 				| XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \
@@ -294,9 +299,9 @@ static inline void kvm_async_pf_hash_reset(struct kvm_vcpu *vcpu)
 static void kvm_on_user_return(struct user_return_notifier *urn)
 {
 	unsigned slot;
-	struct kvm_shared_msrs *locals
-		= container_of(urn, struct kvm_shared_msrs, urn);
-	struct kvm_shared_msr_values *values;
+	struct kvm_user_return_msrs *msrs
+		= container_of(urn, struct kvm_user_return_msrs, urn);
+	struct kvm_user_return_msr_values *values;
 	unsigned long flags;
 
 	/*
@@ -304,73 +309,73 @@ static void kvm_on_user_return(struct user_return_notifier *urn)
 	 * interrupted and executed through kvm_arch_hardware_disable()
 	 */
 	local_irq_save(flags);
-	if (locals->registered) {
-		locals->registered = false;
+	if (msrs->registered) {
+		msrs->registered = false;
 		user_return_notifier_unregister(urn);
 	}
 	local_irq_restore(flags);
-	for (slot = 0; slot < shared_msrs_global.nr; ++slot) {
-		values = &locals->values[slot];
+	for (slot = 0; slot < user_return_msrs_global.nr; ++slot) {
+		values = &msrs->values[slot];
 		if (values->host != values->curr) {
-			wrmsrl(shared_msrs_global.msrs[slot], values->host);
+			wrmsrl(user_return_msrs_global.msrs[slot], values->host);
 			values->curr = values->host;
 		}
 	}
 }
 
-void kvm_define_shared_msr(unsigned slot, u32 msr)
+void kvm_define_user_return_msr(unsigned slot, u32 msr)
 {
-	BUG_ON(slot >= KVM_NR_SHARED_MSRS);
-	shared_msrs_global.msrs[slot] = msr;
-	if (slot >= shared_msrs_global.nr)
-		shared_msrs_global.nr = slot + 1;
+	BUG_ON(slot >= KVM_MAX_NR_USER_RETURN_MSRS);
+	user_return_msrs_global.msrs[slot] = msr;
+	if (slot >= user_return_msrs_global.nr)
+		user_return_msrs_global.nr = slot + 1;
 }
-EXPORT_SYMBOL_GPL(kvm_define_shared_msr);
+EXPORT_SYMBOL_GPL(kvm_define_user_return_msr);
 
-static void kvm_shared_msr_cpu_online(void)
+static void kvm_user_return_msr_cpu_online(void)
 {
 	unsigned int cpu = smp_processor_id();
-	struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
+	struct kvm_user_return_msrs *msrs = per_cpu_ptr(user_return_msrs, cpu);
 	u64 value;
 	int i;
 
-	for (i = 0; i < shared_msrs_global.nr; ++i) {
-		rdmsrl_safe(shared_msrs_global.msrs[i], &value);
-		smsr->values[i].host = value;
-		smsr->values[i].curr = value;
+	for (i = 0; i < user_return_msrs_global.nr; ++i) {
+		rdmsrl_safe(user_return_msrs_global.msrs[i], &value);
+		msrs->values[i].host = value;
+		msrs->values[i].curr = value;
 	}
 }
 
-int kvm_set_shared_msr(unsigned slot, u64 value, u64 mask)
+int kvm_set_user_return_msr(unsigned slot, u64 value, u64 mask)
 {
 	unsigned int cpu = smp_processor_id();
-	struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
+	struct kvm_user_return_msrs *msrs = per_cpu_ptr(user_return_msrs, cpu);
 	int err;
 
-	value = (value & mask) | (smsr->values[slot].host & ~mask);
-	if (value == smsr->values[slot].curr)
+	value = (value & mask) | (msrs->values[slot].host & ~mask);
+	if (value == msrs->values[slot].curr)
 		return 0;
-	err = wrmsrl_safe(shared_msrs_global.msrs[slot], value);
+	err = wrmsrl_safe(user_return_msrs_global.msrs[slot], value);
 	if (err)
 		return 1;
 
-	smsr->values[slot].curr = value;
-	if (!smsr->registered) {
-		smsr->urn.on_user_return = kvm_on_user_return;
-		user_return_notifier_register(&smsr->urn);
-		smsr->registered = true;
+	msrs->values[slot].curr = value;
+	if (!msrs->registered) {
+		msrs->urn.on_user_return = kvm_on_user_return;
+		user_return_notifier_register(&msrs->urn);
+		msrs->registered = true;
 	}
 	return 0;
 }
-EXPORT_SYMBOL_GPL(kvm_set_shared_msr);
+EXPORT_SYMBOL_GPL(kvm_set_user_return_msr);
 
 static void drop_user_return_notifiers(void)
 {
 	unsigned int cpu = smp_processor_id();
-	struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
+	struct kvm_user_return_msrs *msrs = per_cpu_ptr(user_return_msrs, cpu);
 
-	if (smsr->registered)
-		kvm_on_user_return(&smsr->urn);
+	if (msrs->registered)
+		kvm_on_user_return(&msrs->urn);
 }
 
 u64 kvm_get_apic_base(struct kvm_vcpu *vcpu)
@@ -7512,9 +7517,9 @@ int kvm_arch_init(void *opaque)
 		goto out_free_x86_fpu_cache;
 	}
 
-	shared_msrs = alloc_percpu(struct kvm_shared_msrs);
-	if (!shared_msrs) {
-		printk(KERN_ERR "kvm: failed to allocate percpu kvm_shared_msrs\n");
+	user_return_msrs = alloc_percpu(struct kvm_user_return_msrs);
+	if (!user_return_msrs) {
+		printk(KERN_ERR "kvm: failed to allocate percpu kvm_user_return_msrs\n");
 		goto out_free_x86_emulator_cache;
 	}
 
@@ -7547,7 +7552,7 @@ int kvm_arch_init(void *opaque)
 	return 0;
 
 out_free_percpu:
-	free_percpu(shared_msrs);
+	free_percpu(user_return_msrs);
 out_free_x86_emulator_cache:
 	kmem_cache_destroy(x86_emulator_cache);
 out_free_x86_fpu_cache:
@@ -7574,7 +7579,7 @@ void kvm_arch_exit(void)
 #endif
 	kvm_x86_ops.hardware_enable = NULL;
 	kvm_mmu_module_exit();
-	free_percpu(shared_msrs);
+	free_percpu(user_return_msrs);
 	kmem_cache_destroy(x86_fpu_cache);
 }
 
@@ -9705,7 +9710,7 @@ int kvm_arch_hardware_enable(void)
 	u64 max_tsc = 0;
 	bool stable, backwards_tsc = false;
 
-	kvm_shared_msr_cpu_online();
+	kvm_user_return_msr_cpu_online();
 	ret = kvm_x86_ops.hardware_enable();
 	if (ret != 0)
 		return ret;
-- 
2.28.0

[PATCH v2 02/15] KVM: VMX: Prepend "MAX_" to MSR array size defines

[Sean Christopherson]

Add "MAX" to the LOADSTORE and so called SHARED MSR defines to make it
more clear that the define controls the array size, as opposed to the
actual number of valid entries that are in the array.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/nested.c |  2 +-
 arch/x86/kvm/vmx/vmx.c    |  6 +++---
 arch/x86/kvm/vmx/vmx.h    | 10 +++++-----
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index b6ce9ce91029..f818a406302a 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1040,7 +1040,7 @@ static void prepare_vmx_msr_autostore_list(struct kvm_vcpu *vcpu,
 	in_vmcs12_store_list = nested_msr_store_list_has_msr(vcpu, msr_index);
 
 	if (in_vmcs12_store_list && !in_autostore_list) {
-		if (autostore->nr == NR_LOADSTORE_MSRS) {
+		if (autostore->nr == MAX_NR_LOADSTORE_MSRS) {
 			/*
 			 * Emulated VMEntry does not fail here.  Instead a less
 			 * accurate value will be returned by
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ae7badc3b5bd..e99f3bbfa6e9 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -929,8 +929,8 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
 	if (!entry_only)
 		j = vmx_find_msr_index(&m->host, msr);
 
-	if ((i < 0 && m->guest.nr == NR_LOADSTORE_MSRS) ||
-		(j < 0 &&  m->host.nr == NR_LOADSTORE_MSRS)) {
+	if ((i < 0 && m->guest.nr == MAX_NR_LOADSTORE_MSRS) ||
+	    (j < 0 &&  m->host.nr == MAX_NR_LOADSTORE_MSRS)) {
 		printk_once(KERN_WARNING "Not enough msr switch entries. "
 				"Can't add msr %x\n", msr);
 		return;
@@ -6850,7 +6850,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 			goto free_vpid;
 	}
 
-	BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != NR_SHARED_MSRS);
+	BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != MAX_NR_SHARED_MSRS);
 
 	for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
 		u32 index = vmx_msr_index[i];
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index d7ec66db5eb8..9a418c274880 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -22,16 +22,16 @@ extern const u32 vmx_msr_index[];
 #define X2APIC_MSR(r) (APIC_BASE_MSR + ((r) >> 4))
 
 #ifdef CONFIG_X86_64
-#define NR_SHARED_MSRS	7
+#define MAX_NR_SHARED_MSRS	7
 #else
-#define NR_SHARED_MSRS	4
+#define MAX_NR_SHARED_MSRS	4
 #endif
 
-#define NR_LOADSTORE_MSRS 8
+#define MAX_NR_LOADSTORE_MSRS	8
 
 struct vmx_msrs {
 	unsigned int		nr;
-	struct vmx_msr_entry	val[NR_LOADSTORE_MSRS];
+	struct vmx_msr_entry	val[MAX_NR_LOADSTORE_MSRS];
 };
 
 struct shared_msr_entry {
@@ -218,7 +218,7 @@ struct vcpu_vmx {
 	u32                   idt_vectoring_info;
 	ulong                 rflags;
 
-	struct shared_msr_entry guest_msrs[NR_SHARED_MSRS];
+	struct shared_msr_entry guest_msrs[MAX_NR_SHARED_MSRS];
 	int                   nmsrs;
 	int                   save_nmsrs;
 	bool                  guest_msrs_ready;
-- 
2.28.0

[PATCH v2 03/15] KVM: VMX: Rename "vmx_find_msr_index" to "vmx_find_loadstore_msr_slot"

[Sean Christopherson]

Add "loadstore" to vmx_find_msr_index() to differentiate it from the so
called shared MSRs helpers (which will soon be renamed), and replace
"index" with "slot" to better convey that the helper returns slot in the
array, not the MSR index (the value that gets stuffed into ECX).

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/nested.c | 16 ++++++++--------
 arch/x86/kvm/vmx/vmx.c    | 10 +++++-----
 arch/x86/kvm/vmx/vmx.h    |  2 +-
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index f818a406302a..87e5d606582e 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -938,11 +938,11 @@ static bool nested_vmx_get_vmexit_msr_value(struct kvm_vcpu *vcpu,
 	 * VM-exit in L0, use the more accurate value.
 	 */
 	if (msr_index == MSR_IA32_TSC) {
-		int index = vmx_find_msr_index(&vmx->msr_autostore.guest,
-					       MSR_IA32_TSC);
+		int i = vmx_find_loadstore_msr_slot(&vmx->msr_autostore.guest,
+						    MSR_IA32_TSC);
 
-		if (index >= 0) {
-			u64 val = vmx->msr_autostore.guest.val[index].value;
+		if (i >= 0) {
+			u64 val = vmx->msr_autostore.guest.val[i].value;
 
 			*data = kvm_read_l1_tsc(vcpu, val);
 			return true;
@@ -1031,12 +1031,12 @@ static void prepare_vmx_msr_autostore_list(struct kvm_vcpu *vcpu,
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct vmx_msrs *autostore = &vmx->msr_autostore.guest;
 	bool in_vmcs12_store_list;
-	int msr_autostore_index;
+	int msr_autostore_slot;
 	bool in_autostore_list;
 	int last;
 
-	msr_autostore_index = vmx_find_msr_index(autostore, msr_index);
-	in_autostore_list = msr_autostore_index >= 0;
+	msr_autostore_slot = vmx_find_loadstore_msr_slot(autostore, msr_index);
+	in_autostore_list = msr_autostore_slot >= 0;
 	in_vmcs12_store_list = nested_msr_store_list_has_msr(vcpu, msr_index);
 
 	if (in_vmcs12_store_list && !in_autostore_list) {
@@ -1057,7 +1057,7 @@ static void prepare_vmx_msr_autostore_list(struct kvm_vcpu *vcpu,
 		autostore->val[last].index = msr_index;
 	} else if (!in_vmcs12_store_list && in_autostore_list) {
 		last = --autostore->nr;
-		autostore->val[msr_autostore_index] = autostore->val[last];
+		autostore->val[msr_autostore_slot] = autostore->val[last];
 	}
 }
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e99f3bbfa6e9..35291fd90ca0 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -824,7 +824,7 @@ static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
 	vm_exit_controls_clearbit(vmx, exit);
 }
 
-int vmx_find_msr_index(struct vmx_msrs *m, u32 msr)
+int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr)
 {
 	unsigned int i;
 
@@ -858,7 +858,7 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
 		}
 		break;
 	}
-	i = vmx_find_msr_index(&m->guest, msr);
+	i = vmx_find_loadstore_msr_slot(&m->guest, msr);
 	if (i < 0)
 		goto skip_guest;
 	--m->guest.nr;
@@ -866,7 +866,7 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
 	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);
 
 skip_guest:
-	i = vmx_find_msr_index(&m->host, msr);
+	i = vmx_find_loadstore_msr_slot(&m->host, msr);
 	if (i < 0)
 		return;
 
@@ -925,9 +925,9 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
 		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
 	}
 
-	i = vmx_find_msr_index(&m->guest, msr);
+	i = vmx_find_loadstore_msr_slot(&m->guest, msr);
 	if (!entry_only)
-		j = vmx_find_msr_index(&m->host, msr);
+		j = vmx_find_loadstore_msr_slot(&m->host, msr);
 
 	if ((i < 0 && m->guest.nr == MAX_NR_LOADSTORE_MSRS) ||
 	    (j < 0 &&  m->host.nr == MAX_NR_LOADSTORE_MSRS)) {
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 9a418c274880..26887082118d 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -353,7 +353,7 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu);
 struct shared_msr_entry *find_msr_entry(struct vcpu_vmx *vmx, u32 msr);
 void pt_update_intercept_for_msr(struct vcpu_vmx *vmx);
 void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp);
-int vmx_find_msr_index(struct vmx_msrs *m, u32 msr);
+int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr);
 void vmx_ept_load_pdptrs(struct kvm_vcpu *vcpu);
 
 #define POSTED_INTR_ON  0
-- 
2.28.0

[PATCH v2 04/15] KVM: VMX: Rename the "shared_msr_entry" struct to "vmx_uret_msr"

[Sean Christopherson]

Rename struct "shared_msr_entry" to "vmx_uret_msr" to align with x86's
rename of "shared_msrs" to "user_return_msrs", and to call out that the
struct is specific to VMX, i.e. not part of the generic "shared_msrs"
framework.  Abbreviate "user_return" as "uret" to keep line lengths
marginally sane and code more or less readable.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/nested.c |  2 +-
 arch/x86/kvm/vmx/vmx.c    | 58 +++++++++++++++++++--------------------
 arch/x86/kvm/vmx/vmx.h    | 10 +++----
 3 files changed, 35 insertions(+), 35 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 87e5d606582e..a275eb94280c 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4257,7 +4257,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
 
 static inline u64 nested_vmx_get_vmcs01_guest_efer(struct vcpu_vmx *vmx)
 {
-	struct shared_msr_entry *efer_msr;
+	struct vmx_uret_msr *efer_msr;
 	unsigned int i;
 
 	if (vm_entry_controls_get(vmx) & VM_ENTRY_LOAD_IA32_EFER)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 35291fd90ca0..0a8f43161966 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -628,28 +628,28 @@ static inline int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
 	int i;
 
 	for (i = 0; i < vmx->nmsrs; ++i)
-		if (vmx_msr_index[vmx->guest_msrs[i].index] == msr)
+		if (vmx_msr_index[vmx->guest_uret_msrs[i].index] == msr)
 			return i;
 	return -1;
 }
 
-struct shared_msr_entry *find_msr_entry(struct vcpu_vmx *vmx, u32 msr)
+struct vmx_uret_msr *find_msr_entry(struct vcpu_vmx *vmx, u32 msr)
 {
 	int i;
 
 	i = __find_msr_index(vmx, msr);
 	if (i >= 0)
-		return &vmx->guest_msrs[i];
+		return &vmx->guest_uret_msrs[i];
 	return NULL;
 }
 
-static int vmx_set_guest_msr(struct vcpu_vmx *vmx, struct shared_msr_entry *msr, u64 data)
+static int vmx_set_guest_msr(struct vcpu_vmx *vmx, struct vmx_uret_msr *msr, u64 data)
 {
 	int ret = 0;
 
 	u64 old_msr_data = msr->data;
 	msr->data = data;
-	if (msr - vmx->guest_msrs < vmx->save_nmsrs) {
+	if (msr - vmx->guest_uret_msrs < vmx->save_nmsrs) {
 		preempt_disable();
 		ret = kvm_set_user_return_msr(msr->index, msr->data, msr->mask);
 		preempt_enable();
@@ -994,8 +994,8 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
 		guest_efer &= ~ignore_bits;
 		guest_efer |= host_efer & ignore_bits;
 
-		vmx->guest_msrs[efer_offset].data = guest_efer;
-		vmx->guest_msrs[efer_offset].mask = ~ignore_bits;
+		vmx->guest_uret_msrs[efer_offset].data = guest_efer;
+		vmx->guest_uret_msrs[efer_offset].mask = ~ignore_bits;
 
 		return true;
 	}
@@ -1143,9 +1143,9 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
 	if (!vmx->guest_msrs_ready) {
 		vmx->guest_msrs_ready = true;
 		for (i = 0; i < vmx->save_nmsrs; ++i)
-			kvm_set_user_return_msr(vmx->guest_msrs[i].index,
-						vmx->guest_msrs[i].data,
-						vmx->guest_msrs[i].mask);
+			kvm_set_user_return_msr(vmx->guest_uret_msrs[i].index,
+						vmx->guest_uret_msrs[i].data,
+						vmx->guest_uret_msrs[i].mask);
 
 	}
 
@@ -1685,11 +1685,11 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu)
  */
 static void move_msr_up(struct vcpu_vmx *vmx, int from, int to)
 {
-	struct shared_msr_entry tmp;
+	struct vmx_uret_msr tmp;
 
-	tmp = vmx->guest_msrs[to];
-	vmx->guest_msrs[to] = vmx->guest_msrs[from];
-	vmx->guest_msrs[from] = tmp;
+	tmp = vmx->guest_uret_msrs[to];
+	vmx->guest_uret_msrs[to] = vmx->guest_uret_msrs[from];
+	vmx->guest_uret_msrs[from] = tmp;
 }
 
 /*
@@ -1800,7 +1800,7 @@ static int vmx_get_msr_feature(struct kvm_msr_entry *msr)
 static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	struct shared_msr_entry *msr;
+	struct vmx_uret_msr *msr;
 	u32 index;
 
 	switch (msr_info->index) {
@@ -1821,7 +1821,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (!msr_info->host_initiated &&
 		    !(vcpu->arch.arch_capabilities & ARCH_CAP_TSX_CTRL_MSR))
 			return 1;
-		goto find_shared_msr;
+		goto find_uret_msr;
 	case MSR_IA32_UMWAIT_CONTROL:
 		if (!msr_info->host_initiated && !vmx_has_waitpkg(vmx))
 			return 1;
@@ -1928,9 +1928,9 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
 			return 1;
-		goto find_shared_msr;
+		goto find_uret_msr;
 	default:
-	find_shared_msr:
+	find_uret_msr:
 		msr = find_msr_entry(vmx, msr_info->index);
 		if (msr) {
 			msr_info->data = msr->data;
@@ -1960,7 +1960,7 @@ static u64 nested_vmx_truncate_sysenter_addr(struct kvm_vcpu *vcpu,
 static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	struct shared_msr_entry *msr;
+	struct vmx_uret_msr *msr;
 	int ret = 0;
 	u32 msr_index = msr_info->index;
 	u64 data = msr_info->data;
@@ -2064,7 +2064,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			return 1;
 		if (data & ~(TSX_CTRL_RTM_DISABLE | TSX_CTRL_CPUID_CLEAR))
 			return 1;
-		goto find_shared_msr;
+		goto find_uret_msr;
 	case MSR_IA32_PRED_CMD:
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
@@ -2201,10 +2201,10 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		/* Check reserved bit, higher 32 bits should be zero */
 		if ((data >> 32) != 0)
 			return 1;
-		goto find_shared_msr;
+		goto find_uret_msr;
 
 	default:
-	find_shared_msr:
+	find_uret_msr:
 		msr = find_msr_entry(vmx, msr_index);
 		if (msr)
 			ret = vmx_set_guest_msr(vmx, msr, data);
@@ -2837,7 +2837,7 @@ static void enter_rmode(struct kvm_vcpu *vcpu)
 void vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	struct shared_msr_entry *msr = find_msr_entry(vmx, MSR_EFER);
+	struct vmx_uret_msr *msr = find_msr_entry(vmx, MSR_EFER);
 
 	if (!msr)
 		return;
@@ -6850,7 +6850,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 			goto free_vpid;
 	}
 
-	BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != MAX_NR_SHARED_MSRS);
+	BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != MAX_NR_USER_RETURN_MSRS);
 
 	for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
 		u32 index = vmx_msr_index[i];
@@ -6862,8 +6862,8 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 		if (wrmsr_safe(index, data_low, data_high) < 0)
 			continue;
 
-		vmx->guest_msrs[j].index = i;
-		vmx->guest_msrs[j].data = 0;
+		vmx->guest_uret_msrs[j].index = i;
+		vmx->guest_uret_msrs[j].data = 0;
 		switch (index) {
 		case MSR_IA32_TSX_CTRL:
 			/*
@@ -6871,10 +6871,10 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 			 * let's avoid changing CPUID bits under the host
 			 * kernel's feet.
 			 */
-			vmx->guest_msrs[j].mask = ~(u64)TSX_CTRL_CPUID_CLEAR;
+			vmx->guest_uret_msrs[j].mask = ~(u64)TSX_CTRL_CPUID_CLEAR;
 			break;
 		default:
-			vmx->guest_msrs[j].mask = -1ull;
+			vmx->guest_uret_msrs[j].mask = -1ull;
 			break;
 		}
 		++vmx->nmsrs;
@@ -7240,7 +7240,7 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 		update_intel_pt_cfg(vcpu);
 
 	if (boot_cpu_has(X86_FEATURE_RTM)) {
-		struct shared_msr_entry *msr;
+		struct vmx_uret_msr *msr;
 		msr = find_msr_entry(vmx, MSR_IA32_TSX_CTRL);
 		if (msr) {
 			bool enabled = guest_cpuid_has(vcpu, X86_FEATURE_RTM);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 26887082118d..757cb35a6895 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -22,9 +22,9 @@ extern const u32 vmx_msr_index[];
 #define X2APIC_MSR(r) (APIC_BASE_MSR + ((r) >> 4))
 
 #ifdef CONFIG_X86_64
-#define MAX_NR_SHARED_MSRS	7
+#define MAX_NR_USER_RETURN_MSRS	7
 #else
-#define MAX_NR_SHARED_MSRS	4
+#define MAX_NR_USER_RETURN_MSRS	4
 #endif
 
 #define MAX_NR_LOADSTORE_MSRS	8
@@ -34,7 +34,7 @@ struct vmx_msrs {
 	struct vmx_msr_entry	val[MAX_NR_LOADSTORE_MSRS];
 };
 
-struct shared_msr_entry {
+struct vmx_uret_msr {
 	unsigned index;
 	u64 data;
 	u64 mask;
@@ -218,7 +218,7 @@ struct vcpu_vmx {
 	u32                   idt_vectoring_info;
 	ulong                 rflags;
 
-	struct shared_msr_entry guest_msrs[MAX_NR_SHARED_MSRS];
+	struct vmx_uret_msr   guest_uret_msrs[MAX_NR_USER_RETURN_MSRS];
 	int                   nmsrs;
 	int                   save_nmsrs;
 	bool                  guest_msrs_ready;
@@ -350,7 +350,7 @@ bool vmx_interrupt_blocked(struct kvm_vcpu *vcpu);
 bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu);
 void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked);
 void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu);
-struct shared_msr_entry *find_msr_entry(struct vcpu_vmx *vmx, u32 msr);
+struct vmx_uret_msr *find_msr_entry(struct vcpu_vmx *vmx, u32 msr);
 void pt_update_intercept_for_msr(struct vcpu_vmx *vmx);
 void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp);
 int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr);
-- 
2.28.0

[PATCH v2 05/15] KVM: VMX: Rename vcpu_vmx's "nmsrs" to "nr_uret_msrs"

[Sean Christopherson]

Rename vcpu_vmx.nsmrs to vcpu_vmx.nr_uret_msrs to explicitly associate
it with the guest_uret_msrs array.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 6 +++---
 arch/x86/kvm/vmx/vmx.h | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0a8f43161966..6048d0e35d11 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -627,7 +627,7 @@ static inline int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
 {
 	int i;
 
-	for (i = 0; i < vmx->nmsrs; ++i)
+	for (i = 0; i < vmx->nr_uret_msrs; ++i)
 		if (vmx_msr_index[vmx->guest_uret_msrs[i].index] == msr)
 			return i;
 	return -1;
@@ -6855,7 +6855,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 	for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
 		u32 index = vmx_msr_index[i];
 		u32 data_low, data_high;
-		int j = vmx->nmsrs;
+		int j = vmx->nr_uret_msrs;
 
 		if (rdmsr_safe(index, &data_low, &data_high) < 0)
 			continue;
@@ -6877,7 +6877,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 			vmx->guest_uret_msrs[j].mask = -1ull;
 			break;
 		}
-		++vmx->nmsrs;
+		++vmx->nr_uret_msrs;
 	}
 
 	err = alloc_loaded_vmcs(&vmx->vmcs01);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 757cb35a6895..e9cd01868389 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -219,7 +219,7 @@ struct vcpu_vmx {
 	ulong                 rflags;
 
 	struct vmx_uret_msr   guest_uret_msrs[MAX_NR_USER_RETURN_MSRS];
-	int                   nmsrs;
+	int                   nr_uret_msrs;
 	int                   save_nmsrs;
 	bool                  guest_msrs_ready;
 #ifdef CONFIG_X86_64
-- 
2.28.0

[PATCH v2 06/15] KVM: VMX: Rename vcpu_vmx's "save_nmsrs" to "nr_active_uret_msrs"

[Sean Christopherson]

Add "uret" into the name of "save_nmsrs" to explicitly associate it with
the guest_uret_msrs array, and replace "save" with "active" (for lack of
a better word) to better describe what is being tracked.  While "save"
is more or less accurate when viewed as a literal description of the
field, e.g. it holds the number of MSRs that were saved into the array
the last time setup_msrs() was invoked, it can easily be misinterpreted
by the reader, e.g. as meaning the number of MSRs that were saved from
hardware at some point in the past, or as the number of MSRs that need
to be saved at some point in the future, both of which are wrong.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 22 +++++++++++-----------
 arch/x86/kvm/vmx/vmx.h |  2 +-
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6048d0e35d11..eefd1c991615 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -649,7 +649,7 @@ static int vmx_set_guest_msr(struct vcpu_vmx *vmx, struct vmx_uret_msr *msr, u64
 
 	u64 old_msr_data = msr->data;
 	msr->data = data;
-	if (msr - vmx->guest_uret_msrs < vmx->save_nmsrs) {
+	if (msr - vmx->guest_uret_msrs < vmx->nr_active_uret_msrs) {
 		preempt_disable();
 		ret = kvm_set_user_return_msr(msr->index, msr->data, msr->mask);
 		preempt_enable();
@@ -1142,7 +1142,7 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
 	 */
 	if (!vmx->guest_msrs_ready) {
 		vmx->guest_msrs_ready = true;
-		for (i = 0; i < vmx->save_nmsrs; ++i)
+		for (i = 0; i < vmx->nr_active_uret_msrs; ++i)
 			kvm_set_user_return_msr(vmx->guest_uret_msrs[i].index,
 						vmx->guest_uret_msrs[i].data,
 						vmx->guest_uret_msrs[i].mask);
@@ -1699,9 +1699,9 @@ static void move_msr_up(struct vcpu_vmx *vmx, int from, int to)
  */
 static void setup_msrs(struct vcpu_vmx *vmx)
 {
-	int save_nmsrs, index;
+	int nr_active_uret_msrs, index;
 
-	save_nmsrs = 0;
+	nr_active_uret_msrs = 0;
 #ifdef CONFIG_X86_64
 	/*
 	 * The SYSCALL MSRs are only needed on long mode guests, and only
@@ -1710,26 +1710,26 @@ static void setup_msrs(struct vcpu_vmx *vmx)
 	if (is_long_mode(&vmx->vcpu) && (vmx->vcpu.arch.efer & EFER_SCE)) {
 		index = __find_msr_index(vmx, MSR_STAR);
 		if (index >= 0)
-			move_msr_up(vmx, index, save_nmsrs++);
+			move_msr_up(vmx, index, nr_active_uret_msrs++);
 		index = __find_msr_index(vmx, MSR_LSTAR);
 		if (index >= 0)
-			move_msr_up(vmx, index, save_nmsrs++);
+			move_msr_up(vmx, index, nr_active_uret_msrs++);
 		index = __find_msr_index(vmx, MSR_SYSCALL_MASK);
 		if (index >= 0)
-			move_msr_up(vmx, index, save_nmsrs++);
+			move_msr_up(vmx, index, nr_active_uret_msrs++);
 	}
 #endif
 	index = __find_msr_index(vmx, MSR_EFER);
 	if (index >= 0 && update_transition_efer(vmx, index))
-		move_msr_up(vmx, index, save_nmsrs++);
+		move_msr_up(vmx, index, nr_active_uret_msrs++);
 	index = __find_msr_index(vmx, MSR_TSC_AUX);
 	if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP))
-		move_msr_up(vmx, index, save_nmsrs++);
+		move_msr_up(vmx, index, nr_active_uret_msrs++);
 	index = __find_msr_index(vmx, MSR_IA32_TSX_CTRL);
 	if (index >= 0)
-		move_msr_up(vmx, index, save_nmsrs++);
+		move_msr_up(vmx, index, nr_active_uret_msrs++);
 
-	vmx->save_nmsrs = save_nmsrs;
+	vmx->nr_active_uret_msrs = nr_active_uret_msrs;
 	vmx->guest_msrs_ready = false;
 
 	if (cpu_has_vmx_msr_bitmap())
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index e9cd01868389..202487d8dc28 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -220,7 +220,7 @@ struct vcpu_vmx {
 
 	struct vmx_uret_msr   guest_uret_msrs[MAX_NR_USER_RETURN_MSRS];
 	int                   nr_uret_msrs;
-	int                   save_nmsrs;
+	int                   nr_active_uret_msrs;
 	bool                  guest_msrs_ready;
 #ifdef CONFIG_X86_64
 	u64		      msr_host_kernel_gs_base;
-- 
2.28.0

[PATCH v2 07/15] KVM: VMX: Rename vcpu_vmx's "guest_msrs_ready" to "guest_uret_msrs_loaded"

[Sean Christopherson]

Add "uret" to "guest_msrs_ready" to explicitly associate it with the
"guest_uret_msrs" array, and replace "ready" with "loaded" to more
precisely reflect what it tracks, e.g. "ready" could be interpreted as
meaning ready for processing (setup_msrs() has run), which is wrong.
"loaded" also aligns with the similar "guest_state_loaded" field.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 8 ++++----
 arch/x86/kvm/vmx/vmx.h | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index eefd1c991615..4da4fc65d459 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1140,8 +1140,8 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
 	 * when guest state is loaded. This happens when guest transitions
 	 * to/from long-mode by setting MSR_EFER.LMA.
 	 */
-	if (!vmx->guest_msrs_ready) {
-		vmx->guest_msrs_ready = true;
+	if (!vmx->guest_uret_msrs_loaded) {
+		vmx->guest_uret_msrs_loaded = true;
 		for (i = 0; i < vmx->nr_active_uret_msrs; ++i)
 			kvm_set_user_return_msr(vmx->guest_uret_msrs[i].index,
 						vmx->guest_uret_msrs[i].data,
@@ -1229,7 +1229,7 @@ static void vmx_prepare_switch_to_host(struct vcpu_vmx *vmx)
 #endif
 	load_fixmap_gdt(raw_smp_processor_id());
 	vmx->guest_state_loaded = false;
-	vmx->guest_msrs_ready = false;
+	vmx->guest_uret_msrs_loaded = false;
 }
 
 #ifdef CONFIG_X86_64
@@ -1730,7 +1730,7 @@ static void setup_msrs(struct vcpu_vmx *vmx)
 		move_msr_up(vmx, index, nr_active_uret_msrs++);
 
 	vmx->nr_active_uret_msrs = nr_active_uret_msrs;
-	vmx->guest_msrs_ready = false;
+	vmx->guest_uret_msrs_loaded = false;
 
 	if (cpu_has_vmx_msr_bitmap())
 		vmx_update_msr_bitmap(&vmx->vcpu);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 202487d8dc28..f90de1fd6319 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -221,7 +221,7 @@ struct vcpu_vmx {
 	struct vmx_uret_msr   guest_uret_msrs[MAX_NR_USER_RETURN_MSRS];
 	int                   nr_uret_msrs;
 	int                   nr_active_uret_msrs;
-	bool                  guest_msrs_ready;
+	bool                  guest_uret_msrs_loaded;
 #ifdef CONFIG_X86_64
 	u64		      msr_host_kernel_gs_base;
 	u64		      msr_guest_kernel_gs_base;
-- 
2.28.0

[PATCH v2 08/15] KVM: VMX: Rename "__find_msr_index" to "__vmx_find_uret_msr"

[Sean Christopherson]

Rename "__find_msr_index" to scope it to VMX, associate it with
guest_uret_msrs, and to avoid conflating "MSR's ECX index" with "MSR's
array index".  Similarly, don't use "slot" in the name so as to avoid
colliding the common x86's half of "user_return_msrs" (the slot in
kvm_user_return_msrs is not the same slot in guest_uret_msrs).

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 4da4fc65d459..ca41ee8fac5d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -623,7 +623,7 @@ static inline bool report_flexpriority(void)
 	return flexpriority_enabled;
 }
 
-static inline int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
+static inline int __vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr)
 {
 	int i;
 
@@ -637,7 +637,7 @@ struct vmx_uret_msr *find_msr_entry(struct vcpu_vmx *vmx, u32 msr)
 {
 	int i;
 
-	i = __find_msr_index(vmx, msr);
+	i = __vmx_find_uret_msr(vmx, msr);
 	if (i >= 0)
 		return &vmx->guest_uret_msrs[i];
 	return NULL;
@@ -1708,24 +1708,24 @@ static void setup_msrs(struct vcpu_vmx *vmx)
 	 * when EFER.SCE is set.
 	 */
 	if (is_long_mode(&vmx->vcpu) && (vmx->vcpu.arch.efer & EFER_SCE)) {
-		index = __find_msr_index(vmx, MSR_STAR);
+		index = __vmx_find_uret_msr(vmx, MSR_STAR);
 		if (index >= 0)
 			move_msr_up(vmx, index, nr_active_uret_msrs++);
-		index = __find_msr_index(vmx, MSR_LSTAR);
+		index = __vmx_find_uret_msr(vmx, MSR_LSTAR);
 		if (index >= 0)
 			move_msr_up(vmx, index, nr_active_uret_msrs++);
-		index = __find_msr_index(vmx, MSR_SYSCALL_MASK);
+		index = __vmx_find_uret_msr(vmx, MSR_SYSCALL_MASK);
 		if (index >= 0)
 			move_msr_up(vmx, index, nr_active_uret_msrs++);
 	}
 #endif
-	index = __find_msr_index(vmx, MSR_EFER);
+	index = __vmx_find_uret_msr(vmx, MSR_EFER);
 	if (index >= 0 && update_transition_efer(vmx, index))
 		move_msr_up(vmx, index, nr_active_uret_msrs++);
-	index = __find_msr_index(vmx, MSR_TSC_AUX);
+	index = __vmx_find_uret_msr(vmx, MSR_TSC_AUX);
 	if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP))
 		move_msr_up(vmx, index, nr_active_uret_msrs++);
-	index = __find_msr_index(vmx, MSR_IA32_TSX_CTRL);
+	index = __vmx_find_uret_msr(vmx, MSR_IA32_TSX_CTRL);
 	if (index >= 0)
 		move_msr_up(vmx, index, nr_active_uret_msrs++);
 
-- 
2.28.0

[PATCH v2 09/15] KVM: VMX: Check guest support for RDTSCP before processing MSR_TSC_AUX

[Sean Christopherson]

Check for RDTSCP support prior to checking if MSR_TSC_AUX is in the uret
MSRs array so that the array lookup and manipulation are back-to-back.
This paves the way toward adding a helper to wrap the lookup and
manipulation.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ca41ee8fac5d..ed9ce25d3807 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1722,9 +1722,11 @@ static void setup_msrs(struct vcpu_vmx *vmx)
 	index = __vmx_find_uret_msr(vmx, MSR_EFER);
 	if (index >= 0 && update_transition_efer(vmx, index))
 		move_msr_up(vmx, index, nr_active_uret_msrs++);
-	index = __vmx_find_uret_msr(vmx, MSR_TSC_AUX);
-	if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP))
-		move_msr_up(vmx, index, nr_active_uret_msrs++);
+	if (guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP)) {
+		index = __vmx_find_uret_msr(vmx, MSR_TSC_AUX);
+		if (index >= 0)
+			move_msr_up(vmx, index, nr_active_uret_msrs++);
+	}
 	index = __vmx_find_uret_msr(vmx, MSR_IA32_TSX_CTRL);
 	if (index >= 0)
 		move_msr_up(vmx, index, nr_active_uret_msrs++);
-- 
2.28.0

[PATCH v2 10/15] KVM: VMX: Move uret MSR lookup into update_transition_efer()

[Sean Christopherson]

Move checking for the existence of MSR_EFER in the uret MSR array into
update_transition_efer() so that the lookup and manipulation of the
array in setup_msrs() occur back-to-back.  This paves the way toward
adding a helper to wrap the lookup and manipulation.

To avoid unnecessary overhead, defer the lookup until the uret array
would actually be modified in update_transition_efer().  EFER obviously
exists on CPUs that support the dedicated VMCS fields for switching
EFER, and EFER must exist for the guest and host EFER.NX value to
diverge, i.e. there is no danger of attempting to read/write EFER when
it doesn't exist.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ed9ce25d3807..f3192855f0fb 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -953,10 +953,11 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
 	m->host.val[j].value = host_val;
 }
 
-static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
+static bool update_transition_efer(struct vcpu_vmx *vmx)
 {
 	u64 guest_efer = vmx->vcpu.arch.efer;
 	u64 ignore_bits = 0;
+	int i;
 
 	/* Shadow paging assumes NX to be available.  */
 	if (!enable_ept)
@@ -988,17 +989,21 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
 		else
 			clear_atomic_switch_msr(vmx, MSR_EFER);
 		return false;
-	} else {
-		clear_atomic_switch_msr(vmx, MSR_EFER);
-
-		guest_efer &= ~ignore_bits;
-		guest_efer |= host_efer & ignore_bits;
-
-		vmx->guest_uret_msrs[efer_offset].data = guest_efer;
-		vmx->guest_uret_msrs[efer_offset].mask = ~ignore_bits;
-
-		return true;
 	}
+
+	i = __vmx_find_uret_msr(vmx, MSR_EFER);
+	if (i < 0)
+		return false;
+
+	clear_atomic_switch_msr(vmx, MSR_EFER);
+
+	guest_efer &= ~ignore_bits;
+	guest_efer |= host_efer & ignore_bits;
+
+	vmx->guest_uret_msrs[i].data = guest_efer;
+	vmx->guest_uret_msrs[i].mask = ~ignore_bits;
+
+	return true;
 }
 
 #ifdef CONFIG_X86_32
@@ -1719,9 +1724,11 @@ static void setup_msrs(struct vcpu_vmx *vmx)
 			move_msr_up(vmx, index, nr_active_uret_msrs++);
 	}
 #endif
-	index = __vmx_find_uret_msr(vmx, MSR_EFER);
-	if (index >= 0 && update_transition_efer(vmx, index))
-		move_msr_up(vmx, index, nr_active_uret_msrs++);
+	if (update_transition_efer(vmx)) {
+		index = __vmx_find_uret_msr(vmx, MSR_EFER);
+		if (index >= 0)
+			move_msr_up(vmx, index, nr_active_uret_msrs++);
+	}
 	if (guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP)) {
 		index = __vmx_find_uret_msr(vmx, MSR_TSC_AUX);
 		if (index >= 0)
-- 
2.28.0

[PATCH v2 11/15] KVM: VMX: Add vmx_setup_uret_msr() to handle lookup and swap

[Sean Christopherson]

Add vmx_setup_uret_msr() to wrap the lookup and manipulation of the uret
MSRs array during setup_msrs().  In addition to consolidating code, this
eliminates move_msr_up(), which while being a very literally description
of the function, isn't exacly helpful in understanding the net effect of
the code.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 49 ++++++++++++++++--------------------------
 1 file changed, 18 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f3192855f0fb..93cf86672764 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1685,12 +1685,15 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu)
 	vmx_clear_hlt(vcpu);
 }
 
-/*
- * Swap MSR entry in host/guest MSR entry array.
- */
-static void move_msr_up(struct vcpu_vmx *vmx, int from, int to)
+static void vmx_setup_uret_msr(struct vcpu_vmx *vmx, unsigned int msr)
 {
 	struct vmx_uret_msr tmp;
+	int from, to;
+
+	from = __vmx_find_uret_msr(vmx, msr);
+	if (from < 0)
+		return;
+	to = vmx->nr_active_uret_msrs++;
 
 	tmp = vmx->guest_uret_msrs[to];
 	vmx->guest_uret_msrs[to] = vmx->guest_uret_msrs[from];
@@ -1704,42 +1707,26 @@ static void move_msr_up(struct vcpu_vmx *vmx, int from, int to)
  */
 static void setup_msrs(struct vcpu_vmx *vmx)
 {
-	int nr_active_uret_msrs, index;
-
-	nr_active_uret_msrs = 0;
+	vmx->guest_uret_msrs_loaded = false;
+	vmx->nr_active_uret_msrs = 0;
 #ifdef CONFIG_X86_64
 	/*
 	 * The SYSCALL MSRs are only needed on long mode guests, and only
 	 * when EFER.SCE is set.
 	 */
 	if (is_long_mode(&vmx->vcpu) && (vmx->vcpu.arch.efer & EFER_SCE)) {
-		index = __vmx_find_uret_msr(vmx, MSR_STAR);
-		if (index >= 0)
-			move_msr_up(vmx, index, nr_active_uret_msrs++);
-		index = __vmx_find_uret_msr(vmx, MSR_LSTAR);
-		if (index >= 0)
-			move_msr_up(vmx, index, nr_active_uret_msrs++);
-		index = __vmx_find_uret_msr(vmx, MSR_SYSCALL_MASK);
-		if (index >= 0)
-			move_msr_up(vmx, index, nr_active_uret_msrs++);
+		vmx_setup_uret_msr(vmx, MSR_STAR);
+		vmx_setup_uret_msr(vmx, MSR_LSTAR);
+		vmx_setup_uret_msr(vmx, MSR_SYSCALL_MASK);
 	}
 #endif
-	if (update_transition_efer(vmx)) {
-		index = __vmx_find_uret_msr(vmx, MSR_EFER);
-		if (index >= 0)
-			move_msr_up(vmx, index, nr_active_uret_msrs++);
-	}
-	if (guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP)) {
-		index = __vmx_find_uret_msr(vmx, MSR_TSC_AUX);
-		if (index >= 0)
-			move_msr_up(vmx, index, nr_active_uret_msrs++);
-	}
-	index = __vmx_find_uret_msr(vmx, MSR_IA32_TSX_CTRL);
-	if (index >= 0)
-		move_msr_up(vmx, index, nr_active_uret_msrs++);
+	if (update_transition_efer(vmx))
+		vmx_setup_uret_msr(vmx, MSR_EFER);
 
-	vmx->nr_active_uret_msrs = nr_active_uret_msrs;
-	vmx->guest_uret_msrs_loaded = false;
+	if (guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP))
+		vmx_setup_uret_msr(vmx, MSR_TSC_AUX);
+
+	vmx_setup_uret_msr(vmx, MSR_IA32_TSX_CTRL);
 
 	if (cpu_has_vmx_msr_bitmap())
 		vmx_update_msr_bitmap(&vmx->vcpu);
-- 
2.28.0

[PATCH v2 12/15] KVM: VMX: Rename "find_msr_entry" to "vmx_find_uret_msr"

[Sean Christopherson]

Rename "find_msr_entry" to scope it to VMX and to associate it with
guest_uret_msrs.  Drop the "entry" so that the function name pairs with
the existing __vmx_find_uret_msr(), which intentionally uses a double
underscore prefix instead of appending "index" or "slot" as those names
are already claimed by other pieces of the user return MSR stack.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/nested.c |  2 +-
 arch/x86/kvm/vmx/vmx.c    | 10 +++++-----
 arch/x86/kvm/vmx/vmx.h    |  2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index a275eb94280c..4de147553778 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4271,7 +4271,7 @@ static inline u64 nested_vmx_get_vmcs01_guest_efer(struct vcpu_vmx *vmx)
 			return vmx->msr_autoload.guest.val[i].value;
 	}
 
-	efer_msr = find_msr_entry(vmx, MSR_EFER);
+	efer_msr = vmx_find_uret_msr(vmx, MSR_EFER);
 	if (efer_msr)
 		return efer_msr->data;
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 93cf86672764..3b4fb9ef511d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -633,7 +633,7 @@ static inline int __vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr)
 	return -1;
 }
 
-struct vmx_uret_msr *find_msr_entry(struct vcpu_vmx *vmx, u32 msr)
+struct vmx_uret_msr *vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr)
 {
 	int i;
 
@@ -1927,7 +1927,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		goto find_uret_msr;
 	default:
 	find_uret_msr:
-		msr = find_msr_entry(vmx, msr_info->index);
+		msr = vmx_find_uret_msr(vmx, msr_info->index);
 		if (msr) {
 			msr_info->data = msr->data;
 			break;
@@ -2201,7 +2201,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 
 	default:
 	find_uret_msr:
-		msr = find_msr_entry(vmx, msr_index);
+		msr = vmx_find_uret_msr(vmx, msr_index);
 		if (msr)
 			ret = vmx_set_guest_msr(vmx, msr, data);
 		else
@@ -2833,7 +2833,7 @@ static void enter_rmode(struct kvm_vcpu *vcpu)
 void vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	struct vmx_uret_msr *msr = find_msr_entry(vmx, MSR_EFER);
+	struct vmx_uret_msr *msr = vmx_find_uret_msr(vmx, MSR_EFER);
 
 	if (!msr)
 		return;
@@ -7237,7 +7237,7 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 
 	if (boot_cpu_has(X86_FEATURE_RTM)) {
 		struct vmx_uret_msr *msr;
-		msr = find_msr_entry(vmx, MSR_IA32_TSX_CTRL);
+		msr = vmx_find_uret_msr(vmx, MSR_IA32_TSX_CTRL);
 		if (msr) {
 			bool enabled = guest_cpuid_has(vcpu, X86_FEATURE_RTM);
 			vmx_set_guest_msr(vmx, msr, enabled ? 0 : TSX_CTRL_RTM_DISABLE);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index f90de1fd6319..05c81fcd184e 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -350,7 +350,7 @@ bool vmx_interrupt_blocked(struct kvm_vcpu *vcpu);
 bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu);
 void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked);
 void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu);
-struct vmx_uret_msr *find_msr_entry(struct vcpu_vmx *vmx, u32 msr);
+struct vmx_uret_msr *vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr);
 void pt_update_intercept_for_msr(struct vcpu_vmx *vmx);
 void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp);
 int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr);
-- 
2.28.0

[PATCH v2 13/15] KVM: VMX: Rename "vmx_set_guest_msr" to "vmx_set_guest_uret_msr"

[Sean Christopherson]

Add "uret" to vmx_set_guest_msr() to explicitly associate it with the
guest_uret_msrs array, and to differentiate it from vmx_set_msr() as
well as VMX's load/store MSRs.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 3b4fb9ef511d..363099ec661d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -643,7 +643,8 @@ struct vmx_uret_msr *vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr)
 	return NULL;
 }
 
-static int vmx_set_guest_msr(struct vcpu_vmx *vmx, struct vmx_uret_msr *msr, u64 data)
+static int vmx_set_guest_uret_msr(struct vcpu_vmx *vmx,
+				  struct vmx_uret_msr *msr, u64 data)
 {
 	int ret = 0;
 
@@ -2203,7 +2204,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	find_uret_msr:
 		msr = vmx_find_uret_msr(vmx, msr_index);
 		if (msr)
-			ret = vmx_set_guest_msr(vmx, msr, data);
+			ret = vmx_set_guest_uret_msr(vmx, msr, data);
 		else
 			ret = kvm_set_msr_common(vcpu, msr_info);
 	}
@@ -7240,7 +7241,7 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 		msr = vmx_find_uret_msr(vmx, MSR_IA32_TSX_CTRL);
 		if (msr) {
 			bool enabled = guest_cpuid_has(vcpu, X86_FEATURE_RTM);
-			vmx_set_guest_msr(vmx, msr, enabled ? 0 : TSX_CTRL_RTM_DISABLE);
+			vmx_set_guest_uret_msr(vmx, msr, enabled ? 0 : TSX_CTRL_RTM_DISABLE);
 		}
 	}
 }
-- 
2.28.0

[PATCH v2 14/15] KVM: VMX: Rename "vmx_msr_index" to "vmx_uret_msrs_list"

[Sean Christopherson]

Rename "vmx_msr_index" to "vmx_uret_msrs_list" to associate it with the
uret MSRs array, and to avoid conflating "MSR's ECX index" with "MSR's
index into an array".  Similarly, don't use "slot" in the name as that
terminology is claimed by the common x86 "user_return_msrs" mechanism.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 363099ec661d..82dde6f77524 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -447,9 +447,9 @@ static unsigned long host_idt_base;
  * will emulate SYSCALL in legacy mode if the vendor string in guest
  * CPUID.0:{EBX,ECX,EDX} is "AuthenticAMD" or "AMDisbetter!" To
  * support this emulation, IA32_STAR must always be included in
- * vmx_msr_index[], even in i386 builds.
+ * vmx_uret_msrs_list[], even in i386 builds.
  */
-const u32 vmx_msr_index[] = {
+const u32 vmx_uret_msrs_list[] = {
 #ifdef CONFIG_X86_64
 	MSR_SYSCALL_MASK, MSR_LSTAR, MSR_CSTAR,
 #endif
@@ -628,7 +628,7 @@ static inline int __vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr)
 	int i;
 
 	for (i = 0; i < vmx->nr_uret_msrs; ++i)
-		if (vmx_msr_index[vmx->guest_uret_msrs[i].index] == msr)
+		if (vmx_uret_msrs_list[vmx->guest_uret_msrs[i].index] == msr)
 			return i;
 	return -1;
 }
@@ -6847,10 +6847,10 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 			goto free_vpid;
 	}
 
-	BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != MAX_NR_USER_RETURN_MSRS);
+	BUILD_BUG_ON(ARRAY_SIZE(vmx_uret_msrs_list) != MAX_NR_USER_RETURN_MSRS);
 
-	for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
-		u32 index = vmx_msr_index[i];
+	for (i = 0; i < ARRAY_SIZE(vmx_uret_msrs_list); ++i) {
+		u32 index = vmx_uret_msrs_list[i];
 		u32 data_low, data_high;
 		int j = vmx->nr_uret_msrs;
 
@@ -7917,8 +7917,8 @@ static __init int hardware_setup(void)
 	store_idt(&dt);
 	host_idt_base = dt.address;
 
-	for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i)
-		kvm_define_user_return_msr(i, vmx_msr_index[i]);
+	for (i = 0; i < ARRAY_SIZE(vmx_uret_msrs_list); ++i)
+		kvm_define_user_return_msr(i, vmx_uret_msrs_list[i]);
 
 	if (setup_vmcs_config(&vmcs_config, &vmx_capability) < 0)
 		return -EIO;
-- 
2.28.0

[PATCH v2 15/15] KVM: VMX: Rename vmx_uret_msr's "index" to "slot"

[Sean Christopherson]

Rename "index" to "slot" in struct vmx_uret_msr to align with the
terminology used by common x86's kvm_user_return_msrs, and to avoid
conflating "MSR's ECX index" with "MSR's index into an array".

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 8 ++++----
 arch/x86/kvm/vmx/vmx.h | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 82dde6f77524..d05b8b194b1e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -628,7 +628,7 @@ static inline int __vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr)
 	int i;
 
 	for (i = 0; i < vmx->nr_uret_msrs; ++i)
-		if (vmx_uret_msrs_list[vmx->guest_uret_msrs[i].index] == msr)
+		if (vmx_uret_msrs_list[vmx->guest_uret_msrs[i].slot] == msr)
 			return i;
 	return -1;
 }
@@ -652,7 +652,7 @@ static int vmx_set_guest_uret_msr(struct vcpu_vmx *vmx,
 	msr->data = data;
 	if (msr - vmx->guest_uret_msrs < vmx->nr_active_uret_msrs) {
 		preempt_disable();
-		ret = kvm_set_user_return_msr(msr->index, msr->data, msr->mask);
+		ret = kvm_set_user_return_msr(msr->slot, msr->data, msr->mask);
 		preempt_enable();
 		if (ret)
 			msr->data = old_msr_data;
@@ -1149,7 +1149,7 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
 	if (!vmx->guest_uret_msrs_loaded) {
 		vmx->guest_uret_msrs_loaded = true;
 		for (i = 0; i < vmx->nr_active_uret_msrs; ++i)
-			kvm_set_user_return_msr(vmx->guest_uret_msrs[i].index,
+			kvm_set_user_return_msr(vmx->guest_uret_msrs[i].slot,
 						vmx->guest_uret_msrs[i].data,
 						vmx->guest_uret_msrs[i].mask);
 
@@ -6859,7 +6859,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 		if (wrmsr_safe(index, data_low, data_high) < 0)
 			continue;
 
-		vmx->guest_uret_msrs[j].index = i;
+		vmx->guest_uret_msrs[j].slot = i;
 		vmx->guest_uret_msrs[j].data = 0;
 		switch (index) {
 		case MSR_IA32_TSX_CTRL:
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 05c81fcd184e..7b7f7f38c362 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -35,7 +35,7 @@ struct vmx_msrs {
 };
 
 struct vmx_uret_msr {
-	unsigned index;
+	unsigned int slot; /* The MSR's slot in kvm_user_return_msrs. */
 	u64 data;
 	u64 mask;
 };
-- 
2.28.0

Re: [PATCH v2 03/15] KVM: VMX: Rename "vmx_find_msr_index" to "vmx_find_loadstore_msr_slot"

[Paolo Bonzini]

On 23/09/20 20:03, Sean Christopherson wrote:
> Add "loadstore" to vmx_find_msr_index() to differentiate it from the so
> called shared MSRs helpers (which will soon be renamed), and replace
> "index" with "slot" to better convey that the helper returns slot in the
> array, not the MSR index (the value that gets stuffed into ECX).
> 
> No functional change intended.

"slot" is definitely better, I'll adjust SVM to use it too.

Paolo

> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
>  arch/x86/kvm/vmx/nested.c | 16 ++++++++--------
>  arch/x86/kvm/vmx/vmx.c    | 10 +++++-----
>  arch/x86/kvm/vmx/vmx.h    |  2 +-
>  3 files changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index f818a406302a..87e5d606582e 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -938,11 +938,11 @@ static bool nested_vmx_get_vmexit_msr_value(struct kvm_vcpu *vcpu,
>  	 * VM-exit in L0, use the more accurate value.
>  	 */
>  	if (msr_index == MSR_IA32_TSC) {
> -		int index = vmx_find_msr_index(&vmx->msr_autostore.guest,
> -					       MSR_IA32_TSC);
> +		int i = vmx_find_loadstore_msr_slot(&vmx->msr_autostore.guest,
> +						    MSR_IA32_TSC);
>  
> -		if (index >= 0) {
> -			u64 val = vmx->msr_autostore.guest.val[index].value;
> +		if (i >= 0) {
> +			u64 val = vmx->msr_autostore.guest.val[i].value;
>  
>  			*data = kvm_read_l1_tsc(vcpu, val);
>  			return true;
> @@ -1031,12 +1031,12 @@ static void prepare_vmx_msr_autostore_list(struct kvm_vcpu *vcpu,
>  	struct vcpu_vmx *vmx = to_vmx(vcpu);
>  	struct vmx_msrs *autostore = &vmx->msr_autostore.guest;
>  	bool in_vmcs12_store_list;
> -	int msr_autostore_index;
> +	int msr_autostore_slot;
>  	bool in_autostore_list;
>  	int last;
>  
> -	msr_autostore_index = vmx_find_msr_index(autostore, msr_index);
> -	in_autostore_list = msr_autostore_index >= 0;
> +	msr_autostore_slot = vmx_find_loadstore_msr_slot(autostore, msr_index);
> +	in_autostore_list = msr_autostore_slot >= 0;
>  	in_vmcs12_store_list = nested_msr_store_list_has_msr(vcpu, msr_index);
>  
>  	if (in_vmcs12_store_list && !in_autostore_list) {
> @@ -1057,7 +1057,7 @@ static void prepare_vmx_msr_autostore_list(struct kvm_vcpu *vcpu,
>  		autostore->val[last].index = msr_index;
>  	} else if (!in_vmcs12_store_list && in_autostore_list) {
>  		last = --autostore->nr;
> -		autostore->val[msr_autostore_index] = autostore->val[last];
> +		autostore->val[msr_autostore_slot] = autostore->val[last];
>  	}
>  }
>  
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index e99f3bbfa6e9..35291fd90ca0 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -824,7 +824,7 @@ static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
>  	vm_exit_controls_clearbit(vmx, exit);
>  }
>  
> -int vmx_find_msr_index(struct vmx_msrs *m, u32 msr)
> +int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr)
>  {
>  	unsigned int i;
>  
> @@ -858,7 +858,7 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
>  		}
>  		break;
>  	}
> -	i = vmx_find_msr_index(&m->guest, msr);
> +	i = vmx_find_loadstore_msr_slot(&m->guest, msr);
>  	if (i < 0)
>  		goto skip_guest;
>  	--m->guest.nr;
> @@ -866,7 +866,7 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
>  	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);
>  
>  skip_guest:
> -	i = vmx_find_msr_index(&m->host, msr);
> +	i = vmx_find_loadstore_msr_slot(&m->host, msr);
>  	if (i < 0)
>  		return;
>  
> @@ -925,9 +925,9 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
>  		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
>  	}
>  
> -	i = vmx_find_msr_index(&m->guest, msr);
> +	i = vmx_find_loadstore_msr_slot(&m->guest, msr);
>  	if (!entry_only)
> -		j = vmx_find_msr_index(&m->host, msr);
> +		j = vmx_find_loadstore_msr_slot(&m->host, msr);
>  
>  	if ((i < 0 && m->guest.nr == MAX_NR_LOADSTORE_MSRS) ||
>  	    (j < 0 &&  m->host.nr == MAX_NR_LOADSTORE_MSRS)) {
> diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
> index 9a418c274880..26887082118d 100644
> --- a/arch/x86/kvm/vmx/vmx.h
> +++ b/arch/x86/kvm/vmx/vmx.h
> @@ -353,7 +353,7 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu);
>  struct shared_msr_entry *find_msr_entry(struct vcpu_vmx *vmx, u32 msr);
>  void pt_update_intercept_for_msr(struct vcpu_vmx *vmx);
>  void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp);
> -int vmx_find_msr_index(struct vmx_msrs *m, u32 msr);
> +int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr);
>  void vmx_ept_load_pdptrs(struct kvm_vcpu *vcpu);
>  
>  #define POSTED_INTR_ON  0
>