Hi Xiantao,
Here's an update version of the online_vcpus patch. I agree with you
that the name online_vcpus is more appropriate and I used your trick
to get to struct kvm, so it's a lot cleaner than the old version.
I renamed VM_BASE to KVM_VM_BASE as it seems a more correct name to me
and has less chance of clashing with something. In addition the
parenthesis I added are required to avoid unexpected results from CPP
when you typecast it to struct kvm *.
Cheers,
Jes
Zhang, Xiantao wrote:
Hi, Jes
This patch is okay to me, and still have some minor comments below, and expect them to address in your final patch. Thanks!
1. For readability, I prefer to use online_vcpus intead of online_cpus
2. I don't think it is necessary to save a copy in vcpu's private data, just use the following code to get the kvm pointer and access its non-pointer fileds in vmm module,
struct kvm *get_kvm() {
return (struct kvm*) VM_BASE;
}
After getting kvm pointer, you can use it for vcpu.c's change.
Xiantao
Jes Sorensen wrote:
Hi,
Working on allowing larger max vcpus I'd like to put in this patch
that calculates the number of online cpus. It's a building block for
allowing the larger number of max vcpus without crippling performance
for the smaller cases.
Cheers,
Jes
Account for number of online cpus and use that in loops iterating over
the list of vpus instead of scanning the full array unconditionally.
This patch is a building block to facilitate allowing to bump up
the size of MAX_VCPUS significantly.
Signed-off-by: Jes Sorensen <jes@xxxxxxx>
---
arch/ia64/include/asm/kvm_host.h | 10 ++++++----
arch/ia64/kvm/kvm-ia64.c | 12 ++++++++----
arch/ia64/kvm/vcpu.c | 5 ++++-
3 files changed, 18 insertions(+), 9 deletions(-)
Index: linux-2.6.git/arch/ia64/include/asm/kvm_host.h
===================================================================
--- linux-2.6.git.orig/arch/ia64/include/asm/kvm_host.h
+++ linux-2.6.git/arch/ia64/include/asm/kvm_host.h
@@ -163,10 +163,10 @@
struct kvm_vcpu_data vcpu_data[KVM_MAX_VCPUS];
};
-#define VCPU_BASE(n) KVM_VM_DATA_BASE + \
- offsetof(struct kvm_vm_data, vcpu_data[n])
-#define VM_BASE KVM_VM_DATA_BASE + \
- offsetof(struct kvm_vm_data, kvm_vm_struct)
+#define VCPU_BASE(n) (KVM_VM_DATA_BASE + \
+ offsetof(struct kvm_vm_data, vcpu_data[n]))
+#define KVM_VM_BASE (KVM_VM_DATA_BASE + \
+ offsetof(struct kvm_vm_data, kvm_vm_struct))
#define KVM_MEM_DIRTY_LOG_BASE KVM_VM_DATA_BASE + \
offsetof(struct kvm_vm_data, kvm_mem_dirty_log)
@@ -479,6 +479,8 @@
unsigned long metaphysical_rr4;
unsigned long vmm_init_rr;
+ int online_vcpus;
+
struct kvm_ioapic *vioapic;
struct kvm_vm_stat stat;
struct kvm_sal_data rdv_sal_data;
Index: linux-2.6.git/arch/ia64/kvm/kvm-ia64.c
===================================================================
--- linux-2.6.git.orig/arch/ia64/kvm/kvm-ia64.c
+++ linux-2.6.git/arch/ia64/kvm/kvm-ia64.c
@@ -316,7 +316,7 @@
union ia64_lid lid;
int i;
- for (i = 0; i < KVM_MAX_VCPUS; i++) {
+ for (i = 0; i < kvm->arch.online_vcpus; i++) {
if (kvm->vcpus[i]) {
lid.val = VCPU_LID(kvm->vcpus[i]);
if (lid.id == id && lid.eid == eid)
@@ -390,7 +390,7 @@
call_data.ptc_g_data = p->u.ptc_g_data;
- for (i = 0; i < KVM_MAX_VCPUS; i++) {
+ for (i = 0; i < kvm->arch.online_vcpus; i++) {
if (!kvm->vcpus[i] || kvm->vcpus[i]->arch.mp_state ==
KVM_MP_STATE_UNINITIALIZED ||
vcpu == kvm->vcpus[i])
@@ -825,6 +825,8 @@
return ERR_PTR(-ENOMEM);
kvm_init_vm(kvm);
+ kvm->arch.online_vcpus = 0;
+
return kvm;
}
@@ -1186,7 +1188,7 @@
/*Initialize itc offset for vcpus*/
itc_offset = 0UL - ia64_getreg(_IA64_REG_AR_ITC);
- for (i = 0; i < KVM_MAX_VCPUS; i++) {
+ for (i = 0; i < kvm->arch.online_vcpus; i++) {
v = (struct kvm_vcpu *)((char *)vcpu +
sizeof(struct kvm_vcpu_data) * i);
v->arch.itc_offset = itc_offset;
@@ -1320,6 +1322,8 @@
goto fail;
}
+ kvm->arch.online_vcpus++;
+
return vcpu;
fail:
return ERR_PTR(r);
@@ -1766,7 +1770,7 @@
struct kvm_vcpu *lvcpu = kvm->vcpus[0];
int i;
- for (i = 1; i < KVM_MAX_VCPUS; i++) {
+ for (i = 1; i < kvm->arch.online_vcpus; i++) {
if (!kvm->vcpus[i])
continue;
if (lvcpu->arch.xtp > kvm->vcpus[i]->arch.xtp)
Index: linux-2.6.git/arch/ia64/kvm/vcpu.c
===================================================================
--- linux-2.6.git.orig/arch/ia64/kvm/vcpu.c
+++ linux-2.6.git/arch/ia64/kvm/vcpu.c
@@ -811,12 +811,15 @@
static void vcpu_set_itc(struct kvm_vcpu *vcpu, u64 val)
{
struct kvm_vcpu *v;
+ struct kvm *kvm;
int i;
long itc_offset = val - ia64_getreg(_IA64_REG_AR_ITC);
unsigned long vitv = VCPU(vcpu, itv);
+ kvm = (struct kvm *)KVM_VM_BASE;
+
if (vcpu->vcpu_id == 0) {
- for (i = 0; i < KVM_MAX_VCPUS; i++) {
+ for (i = 0; i < kvm->arch.online_vcpus; i++) {
v = (struct kvm_vcpu *)((char *)vcpu +
sizeof(struct kvm_vcpu_data) * i);
VMX(v, itc_offset) = itc_offset;
