Hi,
This patch allows dynamically sizing the vmm area on ia64. I have left
it with the same size as we used to have with the constants, but it
seems to work going higher. I put in an artificial limit of 64 vcpus for
now anyway as scaling wise it doesn't work well going higher anyway.....
we'll get there :-)
Cheers,
Jes
Make KVM_VM_DATA_SHIFT a variable, making it possible allocate a
larger vm data area, making more space for the struct vcpu_data array.
This allows for increasing the number of vcpus a guest can support.
Signed-off-by: Jes Sorensen <jes@xxxxxxx>
---
arch/ia64/include/asm/kvm_host.h | 14 +++++++++-----
arch/ia64/kvm/kvm-ia64.c | 32 ++++++++++++++++----------------
2 files changed, 25 insertions(+), 21 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
@@ -101,8 +101,7 @@
#define KVM_VM_DATA_OFFSET_SHIFT 30
#define KVM_VM_DATA_OFFSET (__IA64_UL_CONST(1) << KVM_VM_DATA_OFFSET_SHIFT)
-#define KVM_VM_DATA_SHIFT 26
-#define KVM_VM_DATA_SIZE (__IA64_UL_CONST(1) << KVM_VM_DATA_SHIFT)
+#define KVM_VM_DATA_SIZE (__IA64_UL_CONST(1) << kvm_vm_data_shift)
#define KVM_VM_DATA_BASE (KVM_VMM_BASE + KVM_VM_DATA_OFFSET)
#define KVM_P2M_BASE KVM_VM_DATA_BASE
@@ -132,9 +131,14 @@
#ifndef __ASSEMBLY__
+extern int kvm_vm_data_shift;
+
/*Define the max vcpus and memory for Guests.*/
-#define KVM_MAX_VCPUS (KVM_VM_DATA_SIZE - KVM_P2M_SIZE - KVM_VM_STRUCT_SIZE -\
- KVM_MEM_DIRTY_LOG_SIZE) / sizeof(struct kvm_vcpu_data)
+#define KVM_MAX_POSSIBLE_VCPUS (KVM_VM_DATA_SIZE - KVM_P2M_SIZE - \
+ KVM_VM_STRUCT_SIZE - KVM_MEM_DIRTY_LOG_SIZE)/ \
+ sizeof(struct kvm_vcpu_data)
+#define KVM_MAX_VCPUS 64
+
#define KVM_MAX_MEM_SIZE (KVM_P2M_SIZE >> 3 << PAGE_SHIFT)
#define VMM_LOG_LEN 256
@@ -160,7 +164,7 @@
char kvm_p2m[KVM_P2M_SIZE];
char kvm_vm_struct[KVM_VM_STRUCT_SIZE];
char kvm_mem_dirty_log[KVM_MEM_DIRTY_LOG_SIZE];
- struct kvm_vcpu_data vcpu_data[KVM_MAX_VCPUS];
+ struct kvm_vcpu_data vcpu_data[0];
};
#define VCPU_BASE(n) (KVM_VM_DATA_BASE + \
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
@@ -54,6 +54,7 @@
static unsigned long kvm_vm_buffer;
static unsigned long kvm_vm_buffer_size;
unsigned long kvm_vmm_gp;
+int kvm_vm_data_shift = 26; /* currently 26 limits us to 156 vcpus */
static long vp_env_info;
@@ -583,8 +584,7 @@
vcpu->arch.vmm_tr_slot = r;
/*Insert a pairt of tr to map data of vm*/
pte = pte_val(mk_pte_phys(__pa(kvm->arch.vm_base), PAGE_KERNEL));
- r = ia64_itr_entry(0x3, KVM_VM_DATA_BASE,
- pte, KVM_VM_DATA_SHIFT);
+ r = ia64_itr_entry(0x3, KVM_VM_DATA_BASE, pte, kvm_vm_data_shift);
if (r < 0)
goto out;
vcpu->arch.vm_tr_slot = r;
@@ -749,14 +749,14 @@
BUG_ON(sizeof(struct kvm) > KVM_VM_STRUCT_SIZE);
- vm_base = __get_free_pages(GFP_KERNEL, get_order(KVM_VM_DATA_SIZE));
+ vm_base = __get_free_pages(GFP_KERNEL, kvm_vm_data_shift - PAGE_SHIFT);
if (!vm_base)
return ERR_PTR(-ENOMEM);
- memset((void *)vm_base, 0, KVM_VM_DATA_SIZE);
+ memset((void *)vm_base, 0, (1 << kvm_vm_data_shift));
kvm = (struct kvm *)(vm_base +
- offsetof(struct kvm_vm_data, kvm_vm_struct));
+ offsetof(struct kvm_vm_data, kvm_vm_struct));
kvm->arch.vm_base = vm_base;
printk(KERN_DEBUG"kvm: vm's data area:0x%lx\n", vm_base);
@@ -1039,7 +1039,8 @@
{
if (!kvm_vmm_base && (kvm_vm_buffer_size < KVM_VM_BUFFER_SIZE)) {
kvm_vmm_base = __get_free_pages(GFP_KERNEL,
- get_order(KVM_VMM_SIZE));
+ KVM_VMM_SHIFT - PAGE_SHIFT);
+
if (!kvm_vmm_base)
return -ENOMEM;
@@ -1286,20 +1287,19 @@
return r;
}
-struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
- unsigned int id)
+struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
struct kvm_vcpu *vcpu;
unsigned long vm_base = kvm->arch.vm_base;
- int r;
- int cpu;
+ int r, cpu, max_cpu;
BUG_ON(sizeof(struct kvm_vcpu) > VCPU_STRUCT_SIZE/2);
r = -EINVAL;
- if (id >= KVM_MAX_VCPUS) {
- printk(KERN_ERR"kvm: Can't configure vcpus > %ld",
- KVM_MAX_VCPUS);
+
+ max_cpu = min_t(long, KVM_MAX_VCPUS, KVM_MAX_POSSIBLE_VCPUS);
+ if (id >= max_cpu) {
+ printk(KERN_ERR "kvm: Can't configure vcpus > %i", max_cpu);
goto fail;
}
@@ -1353,12 +1353,12 @@
static void free_kvm(struct kvm *kvm)
{
unsigned long vm_base = kvm->arch.vm_base;
+ unsigned long vm_size = 1UL << kvm_vm_data_shift;
if (vm_base) {
- memset((void *)vm_base, 0, KVM_VM_DATA_SIZE);
- free_pages(vm_base, get_order(KVM_VM_DATA_SIZE));
+ memset((void *)vm_base, 0, vm_size);
+ free_pages(vm_base, kvm_vm_data_shift - PAGE_SHIFT);
}
-
}
static void kvm_release_vm_pages(struct kvm *kvm)
