[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 2/3] x86/vmx: optimize vmx_read/write_guest_msr()
Replace linear scan with vmx_find_msr(). This way the time complexity of searching for required MSR reduces from linear to logarithmic. Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx> Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> --- v2 --> v3: - no changes xen/arch/x86/hvm/vmx/vmcs.c | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-) diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c index 977106f..0dcb938 100644 --- a/xen/arch/x86/hvm/vmx/vmcs.c +++ b/xen/arch/x86/hvm/vmx/vmcs.c @@ -1360,17 +1360,12 @@ struct vmx_msr_entry *vmx_find_msr(u32 msr, int type) int vmx_read_guest_msr(u32 msr, u64 *val) { - struct vcpu *curr = current; - unsigned int i, msr_count = curr->arch.hvm_vmx.msr_count; - const struct vmx_msr_entry *msr_area = curr->arch.hvm_vmx.msr_area; + struct vmx_msr_entry *ent; - for ( i = 0; i < msr_count; i++ ) + if ( (ent = vmx_find_msr(msr, VMX_GUEST_MSR)) != NULL ) { - if ( msr_area[i].index == msr ) - { - *val = msr_area[i].data; - return 0; - } + *val = ent->data; + return 0; } return -ESRCH; @@ -1378,17 +1373,12 @@ int vmx_read_guest_msr(u32 msr, u64 *val) int vmx_write_guest_msr(u32 msr, u64 val) { - struct vcpu *curr = current; - unsigned int i, msr_count = curr->arch.hvm_vmx.msr_count; - struct vmx_msr_entry *msr_area = curr->arch.hvm_vmx.msr_area; + struct vmx_msr_entry *ent; - for ( i = 0; i < msr_count; i++ ) + if ( (ent = vmx_find_msr(msr, VMX_GUEST_MSR)) != NULL ) { - if ( msr_area[i].index == msr ) - { - msr_area[i].data = val; - return 0; - } + ent->data = val; + return 0; } return -ESRCH; -- 2.9.3 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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