Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull second batch of kvm updates from Paolo Bonzini:
 "Four changes:

   - x86: work around two nasty cases where a benign exception occurs
     while another is being delivered.  The endless stream of exceptions
     causes an infinite loop in the processor, which not even NMIs or
     SMIs can interrupt; in the virt case, there is no possibility to
     exit to the host either.

   - x86: support for Skylake per-guest TSC rate.  Long supported by
     AMD, the patches mostly move things from there to common
     arch/x86/kvm/ code.

   - generic: remove local_irq_save/restore from the guest entry and
     exit paths when context tracking is enabled.  The patches are a few
     months old, but we discussed them again at kernel summit.  Andy
     will pick up from here and, in 4.5, try to remove it from the user
     entry/exit paths.

   - PPC: Two bug fixes, see merge commit 370289756becc for details"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
  KVM: x86: rename update_db_bp_intercept to update_bp_intercept
  KVM: svm: unconditionally intercept #DB
  KVM: x86: work around infinite loop in microcode when #AC is delivered
  context_tracking: avoid irq_save/irq_restore on guest entry and exit
  context_tracking: remove duplicate enabled check
  KVM: VMX: Dump TSC multiplier in dump_vmcs()
  KVM: VMX: Use a scaled host TSC for guest readings of MSR_IA32_TSC
  KVM: VMX: Setup TSC scaling ratio when a vcpu is loaded
  KVM: VMX: Enable and initialize VMX TSC scaling
  KVM: x86: Use the correct vcpu's TSC rate to compute time scale
  KVM: x86: Move TSC scaling logic out of call-back read_l1_tsc()
  KVM: x86: Move TSC scaling logic out of call-back adjust_tsc_offset()
  KVM: x86: Replace call-back compute_tsc_offset() with a common function
  KVM: x86: Replace call-back set_tsc_khz() with a common function
  KVM: x86: Add a common TSC scaling function
  KVM: x86: Add a common TSC scaling ratio field in kvm_vcpu_arch
  KVM: x86: Collect information for setting TSC scaling ratio
  KVM: x86: declare a few variables as __read_mostly
  KVM: x86: merge handle_mmio_page_fault and handle_mmio_page_fault_common
  KVM: PPC: Book3S HV: Don't dynamically split core when already split
  ...

1 files changed, 38 insertions, 33 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5eb56ed77c1f..87acc5221740 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -107,6 +107,8 @@ static u64 __read_mostly host_xss;
 static bool __read_mostly enable_pml = 1;
 module_param_named(pml, enable_pml, bool, S_IRUGO);
 
+#define KVM_VMX_TSC_MULTIPLIER_MAX     0xffffffffffffffffULL
+
 #define KVM_GUEST_CR0_MASK (X86_CR0_NW | X86_CR0_CD)
 #define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST (X86_CR0_WP | X86_CR0_NE)
 #define KVM_VM_CR0_ALWAYS_ON						\
@@ -1172,6 +1174,12 @@ static inline bool cpu_has_vmx_pml(void)
 	return vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_ENABLE_PML;
 }
 
+static inline bool cpu_has_vmx_tsc_scaling(void)
+{
+	return vmcs_config.cpu_based_2nd_exec_ctrl &
+		SECONDARY_EXEC_TSC_SCALING;
+}
+
 static inline bool report_flexpriority(void)
 {
 	return flexpriority_enabled;
@@ -1631,7 +1639,7 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
 	u32 eb;
 
 	eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) |
-	     (1u << NM_VECTOR) | (1u << DB_VECTOR);
+	     (1u << NM_VECTOR) | (1u << DB_VECTOR) | (1u << AC_VECTOR);
 	if ((vcpu->guest_debug &
 	     (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) ==
 	    (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP))
@@ -2053,6 +2061,12 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 
 		rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
 		vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
+
+		/* Setup TSC multiplier */
+		if (cpu_has_vmx_tsc_scaling())
+			vmcs_write64(TSC_MULTIPLIER,
+				     vcpu->arch.tsc_scaling_ratio);
+
 		vmx->loaded_vmcs->cpu = cpu;
 	}
 
@@ -2357,15 +2371,16 @@ static void setup_msrs(struct vcpu_vmx *vmx)
 
 /*
  * reads and returns guest's timestamp counter "register"
- * guest_tsc = host_tsc + tsc_offset    -- 21.3
+ * guest_tsc = (host_tsc * tsc multiplier) >> 48 + tsc_offset
+ * -- Intel TSC Scaling for Virtualization White Paper, sec 1.3
  */
-static u64 guest_read_tsc(void)
+static u64 guest_read_tsc(struct kvm_vcpu *vcpu)
 {
 	u64 host_tsc, tsc_offset;
 
 	host_tsc = rdtsc();
 	tsc_offset = vmcs_read64(TSC_OFFSET);
-	return host_tsc + tsc_offset;
+	return kvm_scale_tsc(vcpu, host_tsc) + tsc_offset;
 }
 
 /*
@@ -2382,22 +2397,6 @@ static u64 vmx_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc)
 	return host_tsc + tsc_offset;
 }
 
-/*
- * Engage any workarounds for mis-matched TSC rates.  Currently limited to
- * software catchup for faster rates on slower CPUs.
- */
-static void vmx_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
-{
-	if (!scale)
-		return;
-
-	if (user_tsc_khz > tsc_khz) {
-		vcpu->arch.tsc_catchup = 1;
-		vcpu->arch.tsc_always_catchup = 1;
-	} else
-		WARN(1, "user requested TSC rate below hardware speed\n");
-}
-
 static u64 vmx_read_tsc_offset(struct kvm_vcpu *vcpu)
 {
 	return vmcs_read64(TSC_OFFSET);
@@ -2429,7 +2428,7 @@ static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
 	}
 }
 
-static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool host)
+static void vmx_adjust_tsc_offset_guest(struct kvm_vcpu *vcpu, s64 adjustment)
 {
 	u64 offset = vmcs_read64(TSC_OFFSET);
 
@@ -2442,11 +2441,6 @@ static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool ho
 					   offset + adjustment);
 }
 
-static u64 vmx_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
-{
-	return target_tsc - rdtsc();
-}
-
 static bool guest_cpuid_has_vmx(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpuid_entry2 *best = kvm_find_cpuid_entry(vcpu, 1, 0);
@@ -2778,7 +2772,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_EFER:
 		return kvm_get_msr_common(vcpu, msr_info);
 	case MSR_IA32_TSC:
-		msr_info->data = guest_read_tsc();
+		msr_info->data = guest_read_tsc(vcpu);
 		break;
 	case MSR_IA32_SYSENTER_CS:
 		msr_info->data = vmcs_read32(GUEST_SYSENTER_CS);
@@ -3154,7 +3148,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
 			SECONDARY_EXEC_SHADOW_VMCS |
 			SECONDARY_EXEC_XSAVES |
 			SECONDARY_EXEC_ENABLE_PML |
-			SECONDARY_EXEC_PCOMMIT;
+			SECONDARY_EXEC_PCOMMIT |
+			SECONDARY_EXEC_TSC_SCALING;
 		if (adjust_vmx_controls(min2, opt2,
 					MSR_IA32_VMX_PROCBASED_CTLS2,
 					&_cpu_based_2nd_exec_control) < 0)
@@ -5266,6 +5261,9 @@ static int handle_exception(struct kvm_vcpu *vcpu)
 		return handle_rmode_exception(vcpu, ex_no, error_code);
 
 	switch (ex_no) {
+	case AC_VECTOR:
+		kvm_queue_exception_e(vcpu, AC_VECTOR, error_code);
+		return 1;
 	case DB_VECTOR:
 		dr6 = vmcs_readl(EXIT_QUALIFICATION);
 		if (!(vcpu->guest_debug &
@@ -5908,7 +5906,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
 		return 1;
 	}
 
-	ret = handle_mmio_page_fault_common(vcpu, gpa, true);
+	ret = handle_mmio_page_fault(vcpu, gpa, true);
 	if (likely(ret == RET_MMIO_PF_EMULATE))
 		return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) ==
 					      EMULATE_DONE;
@@ -6199,6 +6197,12 @@ static __init int hardware_setup(void)
 	if (!cpu_has_vmx_apicv())
 		enable_apicv = 0;
 
+	if (cpu_has_vmx_tsc_scaling()) {
+		kvm_has_tsc_control = true;
+		kvm_max_tsc_scaling_ratio = KVM_VMX_TSC_MULTIPLIER_MAX;
+		kvm_tsc_scaling_ratio_frac_bits = 48;
+	}
+
 	if (enable_apicv)
 		kvm_x86_ops->update_cr8_intercept = NULL;
 	else {
@@ -8008,6 +8012,9 @@ static void dump_vmcs(void)
 	       vmcs_read32(IDT_VECTORING_INFO_FIELD),
 	       vmcs_read32(IDT_VECTORING_ERROR_CODE));
 	pr_err("TSC Offset = 0x%016lx\n", vmcs_readl(TSC_OFFSET));
+	if (secondary_exec_control & SECONDARY_EXEC_TSC_SCALING)
+		pr_err("TSC Multiplier = 0x%016lx\n",
+		       vmcs_readl(TSC_MULTIPLIER));
 	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW)
 		pr_err("TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));
 	if (pin_based_exec_ctrl & PIN_BASED_POSTED_INTR)
@@ -10752,7 +10759,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
 	.vcpu_load = vmx_vcpu_load,
 	.vcpu_put = vmx_vcpu_put,
 
-	.update_db_bp_intercept = update_exception_bitmap,
+	.update_bp_intercept = update_exception_bitmap,
 	.get_msr = vmx_get_msr,
 	.set_msr = vmx_set_msr,
 	.get_segment_base = vmx_get_segment_base,
@@ -10826,11 +10833,9 @@ static struct kvm_x86_ops vmx_x86_ops = {
 
 	.has_wbinvd_exit = cpu_has_vmx_wbinvd_exit,
 
-	.set_tsc_khz = vmx_set_tsc_khz,
 	.read_tsc_offset = vmx_read_tsc_offset,
 	.write_tsc_offset = vmx_write_tsc_offset,
-	.adjust_tsc_offset = vmx_adjust_tsc_offset,
-	.compute_tsc_offset = vmx_compute_tsc_offset,
+	.adjust_tsc_offset_guest = vmx_adjust_tsc_offset_guest,
 	.read_l1_tsc = vmx_read_l1_tsc,
 
 	.set_tdp_cr3 = vmx_set_cr3,