diff options
| author | Dave Hansen <dave@linux.vnet.ibm.com> | 2009-08-06 14:39:52 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-09-08 20:17:12 -0700 |
| commit | ea618866ead0126be93107cdf700b43e7c1854f3 (patch) | |
| tree | 9ec4d4c05579aaacdcf1537ab2cf2d630b88d7b5 /include | |
| parent | 990c4b98649a36713e5f138d40ea6d81f6e5dae0 (diff) | |
KVM: Reduce stack usage in kvm_pv_mmu_op()
(cherry picked from commit 6ad18fba05228fb1d47cdbc0339fe8b3fca1ca26)
We're in a hot path. We can't use kmalloc() because
it might impact performance. So, we just stick the buffer that
we need into the kvm_vcpu_arch structure. This is used very
often, so it is not really a waste.
We also have to move the buffer structure's definition to the
arch-specific x86 kvm header.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-x86/kvm_host.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h index c2e34c27590..cf7c887165c 100644 --- a/include/asm-x86/kvm_host.h +++ b/include/asm-x86/kvm_host.h @@ -195,6 +195,13 @@ struct kvm_mmu_page { }; }; +struct kvm_pv_mmu_op_buffer { + void *ptr; + unsigned len; + unsigned processed; + char buf[512] __aligned(sizeof(long)); +}; + /* * x86 supports 3 paging modes (4-level 64-bit, 3-level 64-bit, and 2-level * 32-bit). The kvm_mmu structure abstracts the details of the current mmu @@ -237,6 +244,9 @@ struct kvm_vcpu_arch { bool tpr_access_reporting; struct kvm_mmu mmu; + /* only needed in kvm_pv_mmu_op() path, but it's hot so + * put it here to avoid allocation */ + struct kvm_pv_mmu_op_buffer mmu_op_buffer; struct kvm_mmu_memory_cache mmu_pte_chain_cache; struct kvm_mmu_memory_cache mmu_rmap_desc_cache; |