[patch] allow dynamic sizing the kvm vmm area on ia64
Jes Sorensen <[email protected]>
| Newsgroups | org.kernel.vger.kvm-ia64 |
|---|---|
| Message-ID | <[email protected]> |
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
5001-kvm-ia64-scale-vcpu.patch
(text/plain, 4.5 KB)
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 <[email protected]> --- 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)