summaryrefslogtreecommitdiffstats
path: root/arch/x86/kvm/x86.c
diff options
context:
space:
mode:
authorIngo Molnar <mingo@kernel.org>2012-04-14 13:18:27 +0200
committerIngo Molnar <mingo@kernel.org>2012-04-14 13:19:04 +0200
commit6ac1ef482d7ae0c690f1640bf6eb818ff9a2d91e (patch)
tree021cc9f6b477146fcebe6f3be4752abfa2ba18a9 /arch/x86/kvm/x86.c
parent682968e0c425c60f0dde37977e5beb2b12ddc4cc (diff)
parenta385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (diff)
Merge branch 'perf/core' into perf/uprobes
Merge in latest upstream (and the latest perf development tree), to prepare for tooling changes, and also to pick up v3.4 MM changes that the uprobes code needs to take care of. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r--arch/x86/kvm/x86.c412
1 files changed, 318 insertions, 94 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9cbfc069811..4044ce0bf7c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -57,6 +57,7 @@
#include <asm/mtrr.h>
#include <asm/mce.h>
#include <asm/i387.h>
+#include <asm/fpu-internal.h> /* Ugh! */
#include <asm/xcr.h>
#include <asm/pvclock.h>
#include <asm/div64.h>
@@ -96,6 +97,10 @@ EXPORT_SYMBOL_GPL(kvm_has_tsc_control);
u32 kvm_max_guest_tsc_khz;
EXPORT_SYMBOL_GPL(kvm_max_guest_tsc_khz);
+/* tsc tolerance in parts per million - default to 1/2 of the NTP threshold */
+static u32 tsc_tolerance_ppm = 250;
+module_param(tsc_tolerance_ppm, uint, S_IRUGO | S_IWUSR);
+
#define KVM_NR_SHARED_MSRS 16
struct kvm_shared_msrs_global {
@@ -968,50 +973,51 @@ static inline u64 get_kernel_ns(void)
static DEFINE_PER_CPU(unsigned long, cpu_tsc_khz);
unsigned long max_tsc_khz;
-static inline int kvm_tsc_changes_freq(void)
+static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
{
- int cpu = get_cpu();
- int ret = !boot_cpu_has(X86_FEATURE_CONSTANT_TSC) &&
- cpufreq_quick_get(cpu) != 0;
- put_cpu();
- return ret;
+ return pvclock_scale_delta(nsec, vcpu->arch.virtual_tsc_mult,
+ vcpu->arch.virtual_tsc_shift);
}
-u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu)
+static u32 adjust_tsc_khz(u32 khz, s32 ppm)
{
- if (vcpu->arch.virtual_tsc_khz)
- return vcpu->arch.virtual_tsc_khz;
- else
- return __this_cpu_read(cpu_tsc_khz);
+ u64 v = (u64)khz * (1000000 + ppm);
+ do_div(v, 1000000);
+ return v;
}
-static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
+static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz)
{
- u64 ret;
-
- WARN_ON(preemptible());
- if (kvm_tsc_changes_freq())
- printk_once(KERN_WARNING
- "kvm: unreliable cycle conversion on adjustable rate TSC\n");
- ret = nsec * vcpu_tsc_khz(vcpu);
- do_div(ret, USEC_PER_SEC);
- return ret;
-}
+ u32 thresh_lo, thresh_hi;
+ int use_scaling = 0;
-static void kvm_init_tsc_catchup(struct kvm_vcpu *vcpu, u32 this_tsc_khz)
-{
/* Compute a scale to convert nanoseconds in TSC cycles */
kvm_get_time_scale(this_tsc_khz, NSEC_PER_SEC / 1000,
- &vcpu->arch.tsc_catchup_shift,
- &vcpu->arch.tsc_catchup_mult);
+ &vcpu->arch.virtual_tsc_shift,
+ &vcpu->arch.virtual_tsc_mult);
+ vcpu->arch.virtual_tsc_khz = this_tsc_khz;
+
+ /*
+ * Compute the variation in TSC rate which is acceptable
+ * within the range of tolerance and decide if the
+ * rate being applied is within that bounds of the hardware
+ * rate. If so, no scaling or compensation need be done.
+ */
+ thresh_lo = adjust_tsc_khz(tsc_khz, -tsc_tolerance_ppm);
+ thresh_hi = adjust_tsc_khz(tsc_khz, tsc_tolerance_ppm);
+ if (this_tsc_khz < thresh_lo || this_tsc_khz > thresh_hi) {
+ pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", this_tsc_khz, thresh_lo, thresh_hi);
+ use_scaling = 1;
+ }
+ kvm_x86_ops->set_tsc_khz(vcpu, this_tsc_khz, use_scaling);
}
static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
{
- u64 tsc = pvclock_scale_delta(kernel_ns-vcpu->arch.last_tsc_nsec,
- vcpu->arch.tsc_catchup_mult,
- vcpu->arch.tsc_catchup_shift);
- tsc += vcpu->arch.last_tsc_write;
+ u64 tsc = pvclock_scale_delta(kernel_ns-vcpu->arch.this_tsc_nsec,
+ vcpu->arch.virtual_tsc_mult,
+ vcpu->arch.virtual_tsc_shift);
+ tsc += vcpu->arch.this_tsc_write;
return tsc;
}
@@ -1020,48 +1026,88 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data)
struct kvm *kvm = vcpu->kvm;
u64 offset, ns, elapsed;
unsigned long flags;
- s64 sdiff;
+ s64 usdiff;
raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
ns = get_kernel_ns();
elapsed = ns - kvm->arch.last_tsc_nsec;
- sdiff = data - kvm->arch.last_tsc_write;
- if (sdiff < 0)
- sdiff = -sdiff;
+
+ /* n.b - signed multiplication and division required */
+ usdiff = data - kvm->arch.last_tsc_write;
+#ifdef CONFIG_X86_64
+ usdiff = (usdiff * 1000) / vcpu->arch.virtual_tsc_khz;
+#else
+ /* do_div() only does unsigned */
+ asm("idivl %2; xor %%edx, %%edx"
+ : "=A"(usdiff)
+ : "A"(usdiff * 1000), "rm"(vcpu->arch.virtual_tsc_khz));
+#endif
+ do_div(elapsed, 1000);
+ usdiff -= elapsed;
+ if (usdiff < 0)
+ usdiff = -usdiff;
/*
- * Special case: close write to TSC within 5 seconds of
- * another CPU is interpreted as an attempt to synchronize
- * The 5 seconds is to accommodate host load / swapping as
- * well as any reset of TSC during the boot process.
- *
- * In that case, for a reliable TSC, we can match TSC offsets,
- * or make a best guest using elapsed value.
- */
- if (sdiff < nsec_to_cycles(vcpu, 5ULL * NSEC_PER_SEC) &&
- elapsed < 5ULL * NSEC_PER_SEC) {
+ * Special case: TSC write with a small delta (1 second) of virtual
+ * cycle time against real time is interpreted as an attempt to
+ * synchronize the CPU.
+ *
+ * For a reliable TSC, we can match TSC offsets, and for an unstable
+ * TSC, we add elapsed time in this computation. We could let the
+ * compensation code attempt to catch up if we fall behind, but
+ * it's better to try to match offsets from the beginning.
+ */
+ if (usdiff < USEC_PER_SEC &&
+ vcpu->arch.virtual_tsc_khz == kvm->arch.last_tsc_khz) {
if (!check_tsc_unstable()) {
- offset = kvm->arch.last_tsc_offset;
+ offset = kvm->arch.cur_tsc_offset;
pr_debug("kvm: matched tsc offset for %llu\n", data);
} else {
u64 delta = nsec_to_cycles(vcpu, elapsed);
- offset += delta;
+ data += delta;
+ offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
pr_debug("kvm: adjusted tsc offset by %llu\n", delta);
}
- ns = kvm->arch.last_tsc_nsec;
+ } else {
+ /*
+ * We split periods of matched TSC writes into generations.
+ * For each generation, we track the original measured
+ * nanosecond time, offset, and write, so if TSCs are in
+ * sync, we can match exact offset, and if not, we can match
+ * exact software computaion in compute_guest_tsc()
+ *
+ * These values are tracked in kvm->arch.cur_xxx variables.
+ */
+ kvm->arch.cur_tsc_generation++;
+ kvm->arch.cur_tsc_nsec = ns;
+ kvm->arch.cur_tsc_write = data;
+ kvm->arch.cur_tsc_offset = offset;
+ pr_debug("kvm: new tsc generation %u, clock %llu\n",
+ kvm->arch.cur_tsc_generation, data);
}
+
+ /*
+ * We also track th most recent recorded KHZ, write and time to
+ * allow the matching interval to be extended at each write.
+ */
kvm->arch.last_tsc_nsec = ns;
kvm->arch.last_tsc_write = data;
- kvm->arch.last_tsc_offset = offset;
- kvm_x86_ops->write_tsc_offset(vcpu, offset);
- raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
+ kvm->arch.last_tsc_khz = vcpu->arch.virtual_tsc_khz;
/* Reset of TSC must disable overshoot protection below */
vcpu->arch.hv_clock.tsc_timestamp = 0;
- vcpu->arch.last_tsc_write = data;
- vcpu->arch.last_tsc_nsec = ns;
+ vcpu->arch.last_guest_tsc = data;
+
+ /* Keep track of which generation this VCPU has synchronized to */
+ vcpu->arch.this_tsc_generation = kvm->arch.cur_tsc_generation;
+ vcpu->arch.this_tsc_nsec = kvm->arch.cur_tsc_nsec;
+ vcpu->arch.this_tsc_write = kvm->arch.cur_tsc_write;
+
+ kvm_x86_ops->write_tsc_offset(vcpu, offset);
+ raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
}
+
EXPORT_SYMBOL_GPL(kvm_write_tsc);
static int kvm_guest_time_update(struct kvm_vcpu *v)
@@ -1077,7 +1123,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
local_irq_save(flags);
tsc_timestamp = kvm_x86_ops->read_l1_tsc(v);
kernel_ns = get_kernel_ns();
- this_tsc_khz = vcpu_tsc_khz(v);
+ this_tsc_khz = __get_cpu_var(cpu_tsc_khz);
if (unlikely(this_tsc_khz == 0)) {
local_irq_restore(flags);
kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
@@ -1097,7 +1143,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
if (vcpu->tsc_catchup) {
u64 tsc = compute_guest_tsc(v, kernel_ns);
if (tsc > tsc_timestamp) {
- kvm_x86_ops->adjust_tsc_offset(v, tsc - tsc_timestamp);
+ adjust_tsc_offset_guest(v, tsc - tsc_timestamp);
tsc_timestamp = tsc;
}
}
@@ -1129,7 +1175,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
* observed by the guest and ensure the new system time is greater.
*/
max_kernel_ns = 0;
- if (vcpu->hv_clock.tsc_timestamp && vcpu->last_guest_tsc) {
+ if (vcpu->hv_clock.tsc_timestamp) {
max_kernel_ns = vcpu->last_guest_tsc -
vcpu->hv_clock.tsc_timestamp;
max_kernel_ns = pvclock_scale_delta(max_kernel_ns,
@@ -1162,12 +1208,12 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
*/
vcpu->hv_clock.version += 2;
- shared_kaddr = kmap_atomic(vcpu->time_page, KM_USER0);
+ shared_kaddr = kmap_atomic(vcpu->time_page);
memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock,
sizeof(vcpu->hv_clock));
- kunmap_atomic(shared_kaddr, KM_USER0);
+ kunmap_atomic(shared_kaddr);
mark_page_dirty(v->kvm, vcpu->time >> PAGE_SHIFT);
return 0;
@@ -1503,6 +1549,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
case MSR_K7_HWCR:
data &= ~(u64)0x40; /* ignore flush filter disable */
data &= ~(u64)0x100; /* ignore ignne emulation enable */
+ data &= ~(u64)0x8; /* ignore TLB cache disable */
if (data != 0) {
pr_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n",
data);
@@ -1675,6 +1722,16 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
*/
pr_unimpl(vcpu, "ignored wrmsr: 0x%x data %llx\n", msr, data);
break;
+ case MSR_AMD64_OSVW_ID_LENGTH:
+ if (!guest_cpuid_has_osvw(vcpu))
+ return 1;
+ vcpu->arch.osvw.length = data;
+ break;
+ case MSR_AMD64_OSVW_STATUS:
+ if (!guest_cpuid_has_osvw(vcpu))
+ return 1;
+ vcpu->arch.osvw.status = data;
+ break;
default:
if (msr && (msr == vcpu->kvm->arch.xen_hvm_config.msr))
return xen_hvm_config(vcpu, data);
@@ -1959,6 +2016,16 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
*/
data = 0xbe702111;
break;
+ case MSR_AMD64_OSVW_ID_LENGTH:
+ if (!guest_cpuid_has_osvw(vcpu))
+ return 1;
+ data = vcpu->arch.osvw.length;
+ break;
+ case MSR_AMD64_OSVW_STATUS:
+ if (!guest_cpuid_has_osvw(vcpu))
+ return 1;
+ data = vcpu->arch.osvw.status;
+ break;
default:
if (kvm_pmu_msr(vcpu, msr))
return kvm_pmu_get_msr(vcpu, msr, pdata);
@@ -2079,6 +2146,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_XSAVE:
case KVM_CAP_ASYNC_PF:
case KVM_CAP_GET_TSC_KHZ:
+ case KVM_CAP_PCI_2_3:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
@@ -2213,19 +2281,23 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
}
kvm_x86_ops->vcpu_load(vcpu, cpu);
- if (unlikely(vcpu->cpu != cpu) || check_tsc_unstable()) {
- /* Make sure TSC doesn't go backwards */
- s64 tsc_delta;
- u64 tsc;
- tsc = kvm_x86_ops->read_l1_tsc(vcpu);
- tsc_delta = !vcpu->arch.last_guest_tsc ? 0 :
- tsc - vcpu->arch.last_guest_tsc;
+ /* Apply any externally detected TSC adjustments (due to suspend) */
+ if (unlikely(vcpu->arch.tsc_offset_adjustment)) {
+ adjust_tsc_offset_host(vcpu, vcpu->arch.tsc_offset_adjustment);
+ vcpu->arch.tsc_offset_adjustment = 0;
+ set_bit(KVM_REQ_CLOCK_UPDATE, &vcpu->requests);
+ }
+ if (unlikely(vcpu->cpu != cpu) || check_tsc_unstable()) {
+ s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 :
+ native_read_tsc() - vcpu->arch.last_host_tsc;
if (tsc_delta < 0)
mark_tsc_unstable("KVM discovered backwards TSC");
if (check_tsc_unstable()) {
- kvm_x86_ops->adjust_tsc_offset(vcpu, -tsc_delta);
+ u64 offset = kvm_x86_ops->compute_tsc_offset(vcpu,
+ vcpu->arch.last_guest_tsc);
+ kvm_x86_ops->write_tsc_offset(vcpu, offset);
vcpu->arch.tsc_catchup = 1;
}
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
@@ -2242,7 +2314,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->vcpu_put(vcpu);
kvm_put_guest_fpu(vcpu);
- vcpu->arch.last_guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu);
+ vcpu->arch.last_host_tsc = native_read_tsc();
}
static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
@@ -2784,26 +2856,21 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
u32 user_tsc_khz;
r = -EINVAL;
- if (!kvm_has_tsc_control)
- break;
-
user_tsc_khz = (u32)arg;
if (user_tsc_khz >= kvm_max_guest_tsc_khz)
goto out;
- kvm_x86_ops->set_tsc_khz(vcpu, user_tsc_khz);
+ if (user_tsc_khz == 0)
+ user_tsc_khz = tsc_khz;
+
+ kvm_set_tsc_khz(vcpu, user_tsc_khz);
r = 0;
goto out;
}
case KVM_GET_TSC_KHZ: {
- r = -EIO;
- if (check_tsc_unstable())
- goto out;
-
- r = vcpu_tsc_khz(vcpu);
-
+ r = vcpu->arch.virtual_tsc_khz;
goto out;
}
default:
@@ -2814,6 +2881,11 @@ out:
return r;
}
+int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
+{
+ return VM_FAULT_SIGBUS;
+}
+
static int kvm_vm_ioctl_set_tss_addr(struct kvm *kvm, unsigned long addr)
{
int ret;
@@ -2997,6 +3069,8 @@ static void write_protect_slot(struct kvm *kvm,
unsigned long *dirty_bitmap,
unsigned long nr_dirty_pages)
{
+ spin_lock(&kvm->mmu_lock);
+
/* Not many dirty pages compared to # of shadow pages. */
if (nr_dirty_pages < kvm->arch.n_used_mmu_pages) {
unsigned long gfn_offset;
@@ -3004,16 +3078,13 @@ static void write_protect_slot(struct kvm *kvm,
for_each_set_bit(gfn_offset, dirty_bitmap, memslot->npages) {
unsigned long gfn = memslot->base_gfn + gfn_offset;
- spin_lock(&kvm->mmu_lock);
kvm_mmu_rmap_write_protect(kvm, gfn, memslot);
- spin_unlock(&kvm->mmu_lock);
}
kvm_flush_remote_tlbs(kvm);
- } else {
- spin_lock(&kvm->mmu_lock);
+ } else
kvm_mmu_slot_remove_write_access(kvm, memslot->id);
- spin_unlock(&kvm->mmu_lock);
- }
+
+ spin_unlock(&kvm->mmu_lock);
}
/*
@@ -3132,6 +3203,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
r = -EEXIST;
if (kvm->arch.vpic)
goto create_irqchip_unlock;
+ r = -EINVAL;
+ if (atomic_read(&kvm->online_vcpus))
+ goto create_irqchip_unlock;
r = -ENOMEM;
vpic = kvm_create_pic(kvm);
if (vpic) {
@@ -3848,7 +3922,7 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
goto emul_write;
}
- kaddr = kmap_atomic(page, KM_USER0);
+ kaddr = kmap_atomic(page);
kaddr += offset_in_page(gpa);
switch (bytes) {
case 1:
@@ -3866,7 +3940,7 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
default:
BUG();
}
- kunmap_atomic(kaddr, KM_USER0);
+ kunmap_atomic(kaddr);
kvm_release_page_dirty(page);
if (!exchanged)
@@ -4062,6 +4136,11 @@ static int emulator_set_cr(struct x86_emulate_ctxt *ctxt, int cr, ulong val)
return res;
}
+static void emulator_set_rflags(struct x86_emulate_ctxt *ctxt, ulong val)
+{
+ kvm_set_rflags(emul_to_vcpu(ctxt), val);
+}
+
static int emulator_get_cpl(struct x86_emulate_ctxt *ctxt)
{
return kvm_x86_ops->get_cpl(emul_to_vcpu(ctxt));
@@ -4243,6 +4322,7 @@ static struct x86_emulate_ops emulate_ops = {
.set_idt = emulator_set_idt,
.get_cr = emulator_get_cr,
.set_cr = emulator_set_cr,
+ .set_rflags = emulator_set_rflags,
.cpl = emulator_get_cpl,
.get_dr = emulator_get_dr,
.set_dr = emulator_set_dr,
@@ -5287,6 +5367,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
profile_hit(KVM_PROFILING, (void *)rip);
}
+ if (unlikely(vcpu->arch.tsc_always_catchup))
+ kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
kvm_lapic_sync_from_vapic(vcpu);
@@ -5586,15 +5668,15 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
return 0;
}
-int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason,
- bool has_error_code, u32 error_code)
+int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index,
+ int reason, bool has_error_code, u32 error_code)
{
struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
int ret;
init_emulate_ctxt(vcpu);
- ret = emulator_task_switch(ctxt, tss_selector, reason,
+ ret = emulator_task_switch(ctxt, tss_selector, idt_index, reason,
has_error_code, error_code);
if (ret)
@@ -5927,13 +6009,88 @@ int kvm_arch_hardware_enable(void *garbage)
struct kvm *kvm;
struct kvm_vcpu *vcpu;
int i;
+ int ret;
+ u64 local_tsc;
+ u64 max_tsc = 0;
+ bool stable, backwards_tsc = false;
kvm_shared_msr_cpu_online();
- list_for_each_entry(kvm, &vm_list, vm_list)
- kvm_for_each_vcpu(i, vcpu, kvm)
- if (vcpu->cpu == smp_processor_id())
- kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
- return kvm_x86_ops->hardware_enable(garbage);
+ ret = kvm_x86_ops->hardware_enable(garbage);
+ if (ret != 0)
+ return ret;
+
+ local_tsc = native_read_tsc();
+ stable = !check_tsc_unstable();
+ list_for_each_entry(kvm, &vm_list, vm_list) {
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!stable && vcpu->cpu == smp_processor_id())
+ set_bit(KVM_REQ_CLOCK_UPDATE, &vcpu->requests);
+ if (stable && vcpu->arch.last_host_tsc > local_tsc) {
+ backwards_tsc = true;
+ if (vcpu->arch.last_host_tsc > max_tsc)
+ max_tsc = vcpu->arch.last_host_tsc;
+ }
+ }
+ }
+
+ /*
+ * Sometimes, even reliable TSCs go backwards. This happens on
+ * platforms that reset TSC during suspend or hibernate actions, but
+ * maintain synchronization. We must compensate. Fortunately, we can
+ * detect that condition here, which happens early in CPU bringup,
+ * before any KVM threads can be running. Unfortunately, we can't
+ * bring the TSCs fully up to date with real time, as we aren't yet far
+ * enough into CPU bringup that we know how much real time has actually
+ * elapsed; our helper function, get_kernel_ns() will be using boot
+ * variables that haven't been updated yet.
+ *
+ * So we simply find the maximum observed TSC above, then record the
+ * adjustment to TSC in each VCPU. When the VCPU later gets loaded,
+ * the adjustment will be applied. Note that we accumulate
+ * adjustments, in case multiple suspend cycles happen before some VCPU
+ * gets a chance to run again. In the event that no KVM threads get a
+ * chance to run, we will miss the entire elapsed period, as we'll have
+ * reset last_host_tsc, so VCPUs will not have the TSC adjusted and may
+ * loose cycle time. This isn't too big a deal, since the loss will be
+ * uniform across all VCPUs (not to mention the scenario is extremely
+ * unlikely). It is possible that a second hibernate recovery happens
+ * much faster than a first, causing the observed TSC here to be
+ * smaller; this would require additional padding adjustment, which is
+ * why we set last_host_tsc to the local tsc observed here.
+ *
+ * N.B. - this code below runs only on platforms with reliable TSC,
+ * as that is the only way backwards_tsc is set above. Also note
+ * that this runs for ALL vcpus, which is not a bug; all VCPUs should
+ * have the same delta_cyc adjustment applied if backwards_tsc
+ * is detected. Note further, this adjustment is only done once,
+ * as we reset last_host_tsc on all VCPUs to stop this from being
+ * called multiple times (one for each physical CPU bringup).
+ *
+ * Platforms with unnreliable TSCs don't have to deal with this, they
+ * will be compensated by the logic in vcpu_load, which sets the TSC to
+ * catchup mode. This will catchup all VCPUs to real time, but cannot
+ * guarantee that they stay in perfect synchronization.
+ */
+ if (backwards_tsc) {
+ u64 delta_cyc = max_tsc - local_tsc;
+ list_for_each_entry(kvm, &vm_list, vm_list) {
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ vcpu->arch.tsc_offset_adjustment += delta_cyc;
+ vcpu->arch.last_host_tsc = local_tsc;
+ }
+
+ /*
+ * We have to disable TSC offset matching.. if you were
+ * booting a VM while issuing an S4 host suspend....
+ * you may have some problem. Solving this issue is
+ * left as an exercise to the reader.
+ */
+ kvm->arch.last_tsc_nsec = 0;
+ kvm->arch.last_tsc_write = 0;
+ }
+
+ }
+ return 0;
}
void kvm_arch_hardware_disable(void *garbage)
@@ -5957,6 +6114,11 @@ void kvm_arch_check_processor_compat(void *rtn)
kvm_x86_ops->check_processor_compatibility(rtn);
}
+bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu)
+{
+ return irqchip_in_kernel(vcpu->kvm) == (vcpu->arch.apic != NULL);
+}
+
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
struct page *page;
@@ -5979,7 +6141,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
}
vcpu->arch.pio_data = page_address(page);
- kvm_init_tsc_catchup(vcpu, max_tsc_khz);
+ kvm_set_tsc_khz(vcpu, max_tsc_khz);
r = kvm_mmu_create(vcpu);
if (r < 0)
@@ -6031,8 +6193,11 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
free_page((unsigned long)vcpu->arch.pio_data);
}
-int kvm_arch_init_vm(struct kvm *kvm)
+int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
+ if (type)
+ return -EINVAL;
+
INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
@@ -6092,6 +6257,65 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
put_page(kvm->arch.ept_identity_pagetable);
}
+void kvm_arch_free_memslot(struct kvm_memory_slot *free,
+ struct kvm_memory_slot *dont)
+{
+ int i;
+
+ for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+ if (!dont || free->arch.lpage_info[i] != dont->arch.lpage_info[i]) {
+ vfree(free->arch.lpage_info[i]);
+ free->arch.lpage_info[i] = NULL;
+ }
+ }
+}
+
+int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
+{
+ int i;
+
+ for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+ unsigned long ugfn;
+ int lpages;
+ int level = i + 2;
+
+ lpages = gfn_to_index(slot->base_gfn + npages - 1,
+ slot->base_gfn, level) + 1;
+
+ slot->arch.lpage_info[i] =
+ vzalloc(lpages * sizeof(*slot->arch.lpage_info[i]));
+ if (!slot->arch.lpage_info[i])
+ goto out_free;
+
+ if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
+ slot->arch.lpage_info[i][0].write_count = 1;
+ if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
+ slot->arch.lpage_info[i][lpages - 1].write_count = 1;
+ ugfn = slot->userspace_addr >> PAGE_SHIFT;
+ /*
+ * If the gfn and userspace address are not aligned wrt each
+ * other, or if explicitly asked to, disable large page
+ * support for this slot
+ */
+ if ((slot->base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
+ !kvm_largepages_enabled()) {
+ unsigned long j;
+
+ for (j = 0; j < lpages; ++j)
+ slot->arch.lpage_info[i][j].write_count = 1;
+ }
+ }
+
+ return 0;
+
+out_free:
+ for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+ vfree(slot->arch.lpage_info[i]);
+ slot->arch.lpage_info[i] = NULL;
+ }
+ return -ENOMEM;
+}
+
int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
struct kvm_memory_slot old,