Jes Sorensen wrote:
> Zhang, Xiantao wrote:
>> Hi, Jes
>> I found the reason why qemu only supports 16 vcpus. In
>> libkvm/kvm-common.h, the MAX_CPUS is defined as 16 for ia64 side. We
>> should increase this value to 64 or big value you like. Please have
>> a try on your mainframe. Thanks!
>> Xiantao
>
> Xiantao,
>
> You are too fast :-)
>
> With this change I can boot 60 vcpus on my system - thats the limit I
> get from KVM_MAX_VCPUS with your patch from yesterday.
>
Great news!! To fix the slow issue at Qemu intilization stage, I have
wrote a patch which intends to allocate memory when it is on-demand.
Could you help to try it ? Thanks!
Xiantao
diff --git a/arch/ia64/include/asm/kvm_host.h
b/arch/ia64/include/asm/kvm_host.h
index e98f6f0..9f89806 100644
--- a/arch/ia64/include/asm/kvm_host.h
+++ b/arch/ia64/include/asm/kvm_host.h
@@ -39,6 +39,7 @@
#define EXIT_REASON_EXTERNAL_INTERRUPT 6
#define EXIT_REASON_IPI 7
#define EXIT_REASON_PTC_G 8
+#define EXIT_REASON_ALLOC_MEM 9
/*Define vmm address space and vm data space.*/
#define KVM_VMM_SIZE (__IA64_UL_CONST(16)<<20)
@@ -308,6 +309,12 @@ struct kvm_ptc_g {
struct kvm_vcpu *vcpu;
};
+/* Alloc real memory exit */
+struct kvm_alloc_mem {
+ unsigned long gpfn;
+ unsigned long pmt_val;
+};
+
/*Exit control data */
struct exit_ctl_data{
uint32_t exit_reason;
@@ -319,6 +326,7 @@ struct exit_ctl_data{
struct kvm_switch_rr6 rr_data;
struct kvm_ipi_data ipi_data;
struct kvm_ptc_g ptc_g_data;
+ struct kvm_alloc_mem alloc_mem;
} u;
};
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 1343781..b02bc03 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -212,6 +212,8 @@ static int handle_vm_error(struct kvm_vcpu *vcpu,
struct kvm_run *kvm_run)
{
kvm_run->exit_reason = KVM_EXIT_UNKNOWN;
kvm_run->hw.hardware_exit_reason = 1;
+ printk(KERN_ERR"KVM: VM error occurs!");
+
return 0;
}
@@ -480,6 +482,40 @@ static int handle_external_interrupt(struct
kvm_vcpu *vcpu,
return 1;
}
+static int handle_mem_alloc(struct kvm_vcpu *vcpu,
+ struct kvm_run *kvm_run)
+{
+ unsigned long pmt_val, gpfn, pfn, gpfn_off;
+ struct kvm_memory_slot *memslot;
+ struct exit_ctl_data *p = kvm_get_exit_data(vcpu);
+
+ gpfn = p->u.alloc_mem.gpfn;
+
+ spin_lock(&vcpu->kvm->mmu_lock);
+ pmt_val = kvm_get_pmt_entry(vcpu->kvm, gpfn);
+ if (!pmt_val) {
+
+ pfn = gfn_to_pfn(vcpu->kvm, gpfn);
+ if (!pfn_valid(pfn))
+ goto out;
+
+ kvm_set_pmt_entry(vcpu->kvm, gpfn, pfn << PAGE_SHIFT,
+ _PAGE_AR_RWX |
_PAGE_MA_WB);
+
+ memslot = gfn_to_memslot(vcpu->kvm, gpfn);
+ if (!memslot)
+ goto out;
+ gpfn_off = gpfn - memslot->base_gfn;
+ memslot->rmap[gpfn_off] = (unsigned
long)pfn_to_page(pfn);
+ pmt_val = kvm_get_pmt_entry(vcpu->kvm, gpfn);
+ }
+out:
+ spin_unlock(&vcpu->kvm->mmu_lock);
+ p->u.alloc_mem.pmt_val = pmt_val;
+
+ return 1;
+}
+
static int (*kvm_vti_exit_handlers[])(struct kvm_vcpu *vcpu,
struct kvm_run *kvm_run) = {
[EXIT_REASON_VM_PANIC] = handle_vm_error,
@@ -491,6 +527,7 @@ static int (*kvm_vti_exit_handlers[])(struct
kvm_vcpu *vcpu,
[EXIT_REASON_EXTERNAL_INTERRUPT] = handle_external_interrupt,
[EXIT_REASON_IPI] = handle_ipi,
[EXIT_REASON_PTC_G] = handle_global_purge,
+ [EXIT_REASON_ALLOC_MEM] = handle_mem_alloc,
};
@@ -1454,26 +1491,24 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
struct kvm_memory_slot old,
int user_alloc)
{
+
unsigned long i;
unsigned long pfn;
int npages = mem->memory_size >> PAGE_SHIFT;
struct kvm_memory_slot *memslot = &kvm->memslots[mem->slot];
unsigned long base_gfn = memslot->base_gfn;
+ spin_lock(&kvm->mmu_lock);
for (i = 0; i < npages; i++) {
pfn = gfn_to_pfn(kvm, base_gfn + i);
- if (!kvm_is_mmio_pfn(pfn)) {
- kvm_set_pmt_entry(kvm, base_gfn + i,
- pfn << PAGE_SHIFT,
- _PAGE_AR_RWX | _PAGE_MA_WB);
- memslot->rmap[i] = (unsigned
long)pfn_to_page(pfn);
- } else {
+ if (kvm_is_mmio_pfn(pfn)) {
kvm_set_pmt_entry(kvm, base_gfn + i,
GPFN_PHYS_MMIO | (pfn <<
PAGE_SHIFT),
_PAGE_MA_UC);
- memslot->rmap[i] = 0;
- }
+ }
+ memslot->rmap[i] = 0;
}
+ spin_unlock(&kvm->mmu_lock);
return 0;
}
diff --git a/arch/ia64/kvm/misc.h b/arch/ia64/kvm/misc.h
index c2ad19a..f9a656b 100644
--- a/arch/ia64/kvm/misc.h
+++ b/arch/ia64/kvm/misc.h
@@ -41,6 +41,13 @@ static inline void kvm_set_pmt_entry(struct kvm *kvm,
gfn_t gfn,
pmt_base[gfn] = pte;
}
+static inline uint64_t kvm_get_pmt_entry(struct kvm *kvm, gfn_t gfn)
+{
+ uint64_t *pmt_base = kvm_host_get_pmt(kvm);
+
+ return pmt_base[gfn];
+}
+
/*Function for translating host address to guest address*/
static inline void *to_guest(struct kvm *kvm, void *addr)
diff --git a/arch/ia64/kvm/vtlb.c b/arch/ia64/kvm/vtlb.c
index 6b6307a..7d2a805 100644
--- a/arch/ia64/kvm/vtlb.c
+++ b/arch/ia64/kvm/vtlb.c
@@ -570,10 +570,37 @@ void thash_init(struct thash_cb *hcb, u64 sz)
}
}
+static unsigned long alloc_real_maddr(unsigned long gpfn)
+{
+ struct exit_ctl_data *p = ¤t_vcpu->arch.exit_data;
+ unsigned long psr;
+
+ local_irq_save(psr);
+
+ p->exit_reason = EXIT_REASON_ALLOC_MEM;
+ p->u.alloc_mem.gpfn = gpfn;
+ p->u.alloc_mem.pmt_val = 0;
+ vmm_transition(current_vcpu);
+
+ local_irq_restore(psr);
+
+ return p->u.alloc_mem.pmt_val;
+}
+
u64 kvm_get_mpt_entry(u64 gpfn)
{
u64 *base = (u64 *) KVM_P2M_BASE;
- return *(base + gpfn);
+ u64 pmt_val = *(base + gpfn);
+
+ if (!pmt_val) {
+ pmt_val = alloc_real_maddr(gpfn);
+ if (!pmt_val) {
+ //printk(KERN_ERR"kvm: NO Enough memory!\n");
+ panic_vm(current_vcpu);
+ }
+
+ }
+ return pmt_val;
}
u64 kvm_lookup_mpa(u64 gpfn)
> I am going to look into making this go further! :-)
> Regards,
> Jes
Attachment:
allocate_on_demand.patch
Description: allocate_on_demand.patch
