Re: [kvm-devel] [PATCH/RFC 3/4]Introduce "account modifiers" mechanism

Laurent Vivier
2007-08-17T14:13:04Z

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Avi Kivity wrote:
[...]
>
> The normal user/system accounting has the same issue, no? Whereever we
> happen to land (kernel or user) gets the whole tick.
>
> So I think it is okay to have the same limitation for guest time.
>

So this is how it looks like.
PATCH 1 and 2 are always a prerequisite.

Laurent

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Index: kvm/include/linux/sched.h
===================================================================
--- kvm.orig/include/linux/sched.h 2007-08-17 15:07:02.000000000 +0200
+++ kvm/include/linux/sched.h 2007-08-17 15:08:19.000000000 +0200
@@ -1310,6 +1310,7 @@
#define PF_STARTING 0x00000002 /* being created */
#define PF_EXITING 0x00000004 /* getting shut down */
#define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
+#define PF_VCPU 0x00000010 /* I'm a virtual CPU */
#define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
#define PF_SUPERPRIV 0x00000100 /* used super-user privileges */
#define PF_DUMPCORE 0x00000200 /* dumped core */
Index: kvm/kernel/sched.c
===================================================================
--- kvm.orig/kernel/sched.c 2007-08-17 14:42:43.000000000 +0200
+++ kvm/kernel/sched.c 2007-08-17 15:16:20.000000000 +0200
@@ -3246,10 +3246,22 @@
struct rq *rq = this_rq();
cputime64_t tmp;

+ tmp = cputime_to_cputime64(cputime);
+ if (p->flags & PF_VCPU) {
+ p->utime = cputime_add(p->utime, cputime);
+ p->gtime = cputime_add(p->gtime, cputime);
+
+ cpustat->guest = cputime64_add(cpustat->guest, tmp);
+ cpustat->user = cputime64_add(cpustat->user, tmp);
+
+ p->flags &= ~PF_VCPU;
+
+ return;
+ }
+
p->stime = cputime_add(p->stime, cputime);

/* Add system time to cpustat. */
- tmp = cputime_to_cputime64(cputime);
if (hardirq_count() - hardirq_offset)
cpustat->irq = cputime64_add(cpustat->irq, tmp);
else if (softirq_count())

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Index: kvm/drivers/kvm/kvm.h
===================================================================
--- kvm.orig/drivers/kvm/kvm.h 2007-08-17 15:26:16.000000000 +0200
+++ kvm/drivers/kvm/kvm.h 2007-08-17 15:29:46.000000000 +0200
@@ -589,6 +589,19 @@

int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run);

+#ifndef PF_VCPU
+#define PF_VCPU 0 /* no kernel support */
+#endif
+
+static inline void kvm_guest_enter(void)
+{
+ current->flags |= PF_VCPU;
+}
+
+static inline void kvm_guest_exit(void)
+{
+}
+
static inline int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
u32 error_code)
{
Index: kvm/drivers/kvm/svm.c
===================================================================
--- kvm.orig/drivers/kvm/svm.c 2007-08-17 15:26:16.000000000 +0200
+++ kvm/drivers/kvm/svm.c 2007-08-17 15:27:03.000000000 +0200
@@ -1404,6 +1404,7 @@
clgi();

vcpu->guest_mode = 1;
+ kvm_guest_enter();
if (vcpu->requests)
if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
svm_flush_tlb(vcpu);
@@ -1536,6 +1537,7 @@
#endif
: "cc", "memory" );

+ kvm_guest_exit();
vcpu->guest_mode = 0;

if (vcpu->fpu_active) {
Index: kvm/drivers/kvm/vmx.c
===================================================================
--- kvm.orig/drivers/kvm/vmx.c 2007-08-17 15:26:16.000000000 +0200
+++ kvm/drivers/kvm/vmx.c 2007-08-17 15:27:45.000000000 +0200
@@ -2078,6 +2078,7 @@
local_irq_disable();

vcpu->guest_mode = 1;
+ kvm_guest_enter();
if (vcpu->requests)
if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
vmx_flush_tlb(vcpu);
@@ -2198,6 +2199,7 @@
[cr2]"i"(offsetof(struct kvm_vcpu, cr2))
: "cc", "memory" );

+ kvm_guest_exit();
vcpu->guest_mode = 0;
local_irq_enable();