[Qemu-devel] [Patch]KVM: enabling per domain PLE

[Hu, Xuekun]

Setting the same PLE parameter arbitrarily for different
workloads is not a good solution. The solution enables
per domain PLE which gives user ability to set PLE parameter
for different domain for better performance.

Signed-off-by: Xuekun Hu <address@hidden>
---
 arch/x86/include/asm/kvm_host.h |    6 ++++++
 arch/x86/kvm/svm.c              |   21 +++++++++++++++++++++
 arch/x86/kvm/vmx.c              |   32 ++++++++++++++++++++++++++++++--
 arch/x86/kvm/x86.c              |   15 ++++++++++++++-
 include/linux/kvm.h             |    3 +++
 5 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b2e11f4..b54f38b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -569,6 +569,8 @@ struct kvm_arch {
        #ifdef CONFIG_KVM_MMU_AUDIT
        int audit_point;
        #endif
+       int ple_gap;
+       int ple_window;
 };
 
 struct kvm_vm_stat {
@@ -621,6 +623,10 @@ struct kvm_x86_ops {
        int (*hardware_setup)(void);               /* __init */
        void (*hardware_unsetup)(void);            /* __exit */
        bool (*cpu_has_accelerated_tpr)(void);
+       bool (*cpu_has_ple)(void);
+       void (*ple_setup)(struct kvm *kvm);                   /* __init */
+       void (*set_ple_gap)(struct kvm *kvm, int value);
+       void (*set_ple_window)(struct kvm *kvm, int value);
        void (*cpuid_update)(struct kvm_vcpu *vcpu);
 
        /* Create, but do not attach this VCPU */
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d017df3..311ed96 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3976,6 +3976,23 @@ static bool svm_cpu_has_accelerated_tpr(void)
        return false;
 }
 
+static bool cpu_has_svm_ple(void)
+{
+       return false;
+}
+
+static void svm_ple_setup(struct kvm *kvm)
+{
+}
+
+static void svm_set_ple_gap(struct kvm *kvm, int value)
+{
+}
+
+static void svm_set_ple_window(struct kvm *kvm, int value)
+{
+}
+
 static u64 svm_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
 {
        return 0;
@@ -4229,6 +4246,10 @@ static struct kvm_x86_ops svm_x86_ops = {
        .hardware_enable = svm_hardware_enable,
        .hardware_disable = svm_hardware_disable,
        .cpu_has_accelerated_tpr = svm_cpu_has_accelerated_tpr,
+       .cpu_has_ple = cpu_has_svm_ple,
+       .ple_setup = svm_ple_setup,
+       .set_ple_gap = svm_set_ple_gap,
+       .set_ple_window = svm_set_ple_window,
 
        .vcpu_create = svm_create_vcpu,
        .vcpu_free = svm_free_vcpu,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ad6b1dd..b761669 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3805,6 +3805,29 @@ static void ept_set_mmio_spte_mask(void)
        kvm_mmu_set_mmio_spte_mask(0xffull << 49 | 0x6ull);
 }
 
+static void vmx_ple_setup(struct kvm *kvm)
+{
+       /*
+        * set up ple default value
+        */
+       if (ple_gap) {
+               kvm->arch.ple_gap = ple_gap;
+               kvm->arch.ple_window = ple_window;
+       }
+}
+
+static void vmx_set_ple_gap(struct kvm *kvm, int value)
+{
+       if (ple_gap)
+               kvm->arch.ple_gap = value;
+}
+
+static void vmx_set_ple_window(struct kvm *kvm, int value)
+{
+       if (ple_gap)
+               kvm->arch.ple_window = value;
+}
+
 /*
  * Sets up the vmcs for emulated real mode.
  */
@@ -3814,6 +3837,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
        unsigned long a;
 #endif
        int i;
+       struct kvm *kvm = vmx->vcpu.kvm;
 
        /* I/O */
        vmcs_write64(IO_BITMAP_A, __pa(vmx_io_bitmap_a));
@@ -3836,8 +3860,8 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
        }
 
        if (ple_gap) {
-               vmcs_write32(PLE_GAP, ple_gap);
-               vmcs_write32(PLE_WINDOW, ple_window);
+               vmcs_write32(PLE_GAP, kvm->arch.ple_gap);
+               vmcs_write32(PLE_WINDOW, kvm->arch.ple_window);
        }
 
        vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, 0);
@@ -7233,6 +7257,10 @@ static struct kvm_x86_ops vmx_x86_ops = {
        .hardware_enable = hardware_enable,
        .hardware_disable = hardware_disable,
        .cpu_has_accelerated_tpr = report_flexpriority,
+       .cpu_has_ple = cpu_has_vmx_ple,
+       .ple_setup = vmx_ple_setup,
+       .set_ple_gap = vmx_set_ple_gap,
+       .set_ple_window = vmx_set_ple_window,
 
        .vcpu_create = vmx_create_vcpu,
        .vcpu_free = vmx_free_vcpu,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1eefebe..89b8291 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2197,6 +2197,9 @@ int kvm_dev_ioctl_check_extension(long ext)
        case KVM_CAP_VAPIC:
                r = !kvm_x86_ops->cpu_has_accelerated_tpr();
                break;
+       case KVM_CAP_PLE:
+               r = kvm_x86_ops->cpu_has_ple();
+               break;
        case KVM_CAP_NR_VCPUS:
                r = KVM_SOFT_MAX_VCPUS;
                break;
@@ -3462,7 +3465,16 @@ long kvm_arch_vm_ioctl(struct file *filp,
                r = 0;
                break;
        }
-
+       case KVM_SET_PLE_GAP: {
+               kvm_x86_ops->set_ple_gap(kvm, arg);
+               r = 0;
+               break;
+       }
+       case KVM_SET_PLE_WINDOW: {
+               kvm_x86_ops->set_ple_window(kvm, arg);
+               r = 0;
+               break;
+       }
        default:
                ;
        }
@@ -6295,6 +6307,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
        raw_spin_lock_init(&kvm->arch.tsc_write_lock);
        mutex_init(&kvm->arch.apic_map_lock);
 
+       kvm_x86_ops->ple_setup(kvm);
        return 0;
 }
 
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 0a6d6ba..02d499e 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -626,6 +626,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_READONLY_MEM 81
 #endif
 #define KVM_CAP_IRQFD_RESAMPLE 82
+#define KVM_CAP_PLE 83
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -786,6 +787,8 @@ struct kvm_msi {
                                        struct kvm_userspace_memory_region)
 #define KVM_SET_TSS_ADDR          _IO(KVMIO,   0x47)
 #define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO,  0x48, __u64)
+#define KVM_SET_PLE_GAP           _IOW(KVMIO,  0x49, __u32)
+#define KVM_SET_PLE_WINDOW        _IOW(KVMIO,  0x4a, __u32)
 
 /* enable ucontrol for s390 */
 struct kvm_s390_ucas_mapping {