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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-01 08:40:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-01 08:40:25 -0700
commit5778077d03cb25aac9b6a428e18970642fc019e3 (patch)
tree2e3f3da1fb99c3646da5ed9a09644696ca5f2309 /arch/x86/kvm/x86.c
parent65a99597f044c083983f4274ab049c9ec3b9d764 (diff)
parent7e01ebffffedec22cea86ebe94802f909e4579ca (diff)
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm changes from Ingo Molnar: "The biggest changes in this cycle were: - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC) primitives. (Andy Lutomirski) - Add new, comprehensible entry and exit handlers written in C. (Andy Lutomirski) - vm86 mode cleanups and fixes. (Brian Gerst) - 32-bit compat code cleanups. (Brian Gerst) The amount of simplification in low level assembly code is already palpable: arch/x86/entry/entry_32.S | 130 +---- arch/x86/entry/entry_64.S | 197 ++----- but more simplifications are planned. There's also the usual laudry mix of low level changes - see the changelog for details" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits) x86/asm: Drop repeated macro of X86_EFLAGS_AC definition x86/asm/msr: Make wrmsrl() a function x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer x86/asm: Add MONITORX/MWAITX instruction support x86/traps: Weaken context tracking entry assertions x86/asm/tsc: Add rdtscll() merge helper selftests/x86: Add syscall_nt selftest selftests/x86: Disable sigreturn_64 x86/vdso: Emit a GNU hash x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks x86/entry/32: Migrate to C exit path x86/entry/32: Remove 32-bit syscall audit optimizations x86/vm86: Rename vm86->v86flags and v86mask x86/vm86: Rename vm86->vm86_info to user_vm86 x86/vm86: Clean up vm86.h includes x86/vm86: Move the vm86 IRQ definitions to vm86.h x86/vm86: Use the normal pt_regs area for vm86 x86/vm86: Eliminate 'struct kernel_vm86_struct' x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86' x86/vm86: Move vm86 fields out of 'thread_struct' ...
Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r--arch/x86/kvm/x86.c26
1 files changed, 7 insertions, 19 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4bbc2a1676c9..1e7e76e14e89 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1441,20 +1441,8 @@ EXPORT_SYMBOL_GPL(kvm_write_tsc);
static cycle_t read_tsc(void)
{
- cycle_t ret;
- u64 last;
-
- /*
- * Empirically, a fence (of type that depends on the CPU)
- * before rdtsc is enough to ensure that rdtsc is ordered
- * with respect to loads. The various CPU manuals are unclear
- * as to whether rdtsc can be reordered with later loads,
- * but no one has ever seen it happen.
- */
- rdtsc_barrier();
- ret = (cycle_t)vget_cycles();
-
- last = pvclock_gtod_data.clock.cycle_last;
+ cycle_t ret = (cycle_t)rdtsc_ordered();
+ u64 last = pvclock_gtod_data.clock.cycle_last;
if (likely(ret >= last))
return ret;
@@ -1643,7 +1631,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
return 1;
}
if (!use_master_clock) {
- host_tsc = native_read_tsc();
+ host_tsc = rdtsc();
kernel_ns = get_kernel_ns();
}
@@ -2620,7 +2608,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
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;
+ rdtsc() - vcpu->arch.last_host_tsc;
if (tsc_delta < 0)
mark_tsc_unstable("KVM discovered backwards TSC");
if (check_tsc_unstable()) {
@@ -2648,7 +2636,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->vcpu_put(vcpu);
kvm_put_guest_fpu(vcpu);
- vcpu->arch.last_host_tsc = native_read_tsc();
+ vcpu->arch.last_host_tsc = rdtsc();
}
static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
@@ -6387,7 +6375,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
hw_breakpoint_restore();
vcpu->arch.last_guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu,
- native_read_tsc());
+ rdtsc());
vcpu->mode = OUTSIDE_GUEST_MODE;
smp_wmb();
@@ -7196,7 +7184,7 @@ int kvm_arch_hardware_enable(void)
if (ret != 0)
return ret;
- local_tsc = native_read_tsc();
+ local_tsc = rdtsc();
stable = !check_tsc_unstable();
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm_for_each_vcpu(i, vcpu, kvm) {