[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging-4.6] x86/vmx: Internal cleanup for MSR load/save infrastructure
commit a1b8d86c786c12e262221ba5f82aaec16f330ef7 Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> AuthorDate: Mon May 7 11:57:00 2018 +0100 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Tue Aug 14 17:39:56 2018 +0100 x86/vmx: Internal cleanup for MSR load/save infrastructure * Use an arch_vmx_struct local variable to reduce later code volume. * Use start/total instead of msr_area/msr_count. This is in preparation for more finegrained handling with later changes. * Use ent/end pointers (again for preparation), and to make the vmx_add_msr() logic easier to follow. * Make the memory allocation block of vmx_add_msr() unlikely, and calculate virt_to_maddr() just once. No practical change to functionality. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx> (cherry picked from commit 94fda356fcdcc847662a4c9f6cc63511f25c1247) --- xen/arch/x86/hvm/vmx/vmcs.c | 76 +++++++++++++++++++++++++-------------------- 1 file changed, 42 insertions(+), 34 deletions(-) diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c index fcc9a2cb98..a9f5d20424 100644 --- a/xen/arch/x86/hvm/vmx/vmcs.c +++ b/xen/arch/x86/hvm/vmx/vmcs.c @@ -1290,33 +1290,33 @@ static int construct_vmcs(struct vcpu *v) struct vmx_msr_entry *vmx_find_msr(uint32_t msr, enum vmx_msr_list_type type) { struct vcpu *curr = current; - unsigned int msr_count; - struct vmx_msr_entry *msr_area = NULL; - unsigned int i; + struct arch_vmx_struct *vmx = &curr->arch.hvm_vmx; + struct vmx_msr_entry *start = NULL; + unsigned int i, total; switch ( type ) { case VMX_MSR_HOST: - msr_count = curr->arch.hvm_vmx.host_msr_count; - msr_area = curr->arch.hvm_vmx.host_msr_area; + start = vmx->host_msr_area; + total = vmx->host_msr_count; break; case VMX_MSR_GUEST: - msr_count = curr->arch.hvm_vmx.msr_count; - msr_area = curr->arch.hvm_vmx.msr_area; + start = vmx->msr_area; + total = vmx->msr_count; break; default: ASSERT_UNREACHABLE(); } - if ( msr_area == NULL ) + if ( !start ) return NULL; - for ( i = 0; i < msr_count; i++ ) + for ( i = 0; i < total; i++ ) { - if ( msr_area[i].index == msr ) - return &msr_area[i]; + if ( start[i].index == msr ) + return &start[i]; } return NULL; @@ -1325,19 +1325,20 @@ struct vmx_msr_entry *vmx_find_msr(uint32_t msr, enum vmx_msr_list_type type) int vmx_add_msr(uint32_t msr, enum vmx_msr_list_type type) { struct vcpu *curr = current; - unsigned int idx, *msr_count; - struct vmx_msr_entry **msr_area, *msr_area_elem; + struct arch_vmx_struct *vmx = &curr->arch.hvm_vmx; + struct vmx_msr_entry **ptr, *start = NULL, *ent, *end; + unsigned int total; switch ( type ) { case VMX_MSR_HOST: - msr_count = &curr->arch.hvm_vmx.host_msr_count; - msr_area = &curr->arch.hvm_vmx.host_msr_area; + ptr = &vmx->host_msr_area; + total = vmx->host_msr_count; break; case VMX_MSR_GUEST: - msr_count = &curr->arch.hvm_vmx.msr_count; - msr_area = &curr->arch.hvm_vmx.msr_area; + ptr = &vmx->msr_area; + total = vmx->msr_count; break; default: @@ -1345,48 +1346,55 @@ int vmx_add_msr(uint32_t msr, enum vmx_msr_list_type type) return -EINVAL; } - if ( *msr_area == NULL ) + /* Allocate memory on first use. */ + if ( unlikely(!*ptr) ) { - if ( (*msr_area = alloc_xenheap_page()) == NULL ) + paddr_t addr; + + if ( (*ptr = alloc_xenheap_page()) == NULL ) return -ENOMEM; + addr = virt_to_maddr(*ptr); + switch ( type ) { case VMX_MSR_HOST: - __vmwrite(VM_EXIT_MSR_LOAD_ADDR, virt_to_maddr(*msr_area)); + __vmwrite(VM_EXIT_MSR_LOAD_ADDR, addr); break; case VMX_MSR_GUEST: - __vmwrite(VM_EXIT_MSR_STORE_ADDR, virt_to_maddr(*msr_area)); - __vmwrite(VM_ENTRY_MSR_LOAD_ADDR, virt_to_maddr(*msr_area)); + __vmwrite(VM_EXIT_MSR_STORE_ADDR, addr); + __vmwrite(VM_ENTRY_MSR_LOAD_ADDR, addr); break; } } - for ( idx = 0; idx < *msr_count; idx++ ) - if ( (*msr_area)[idx].index == msr ) + start = *ptr; + end = start + total; + + for ( ent = start; ent < end && ent->index <= msr; ++ent ) + if ( ent->index == msr ) return 0; - if ( *msr_count == (PAGE_SIZE / sizeof(struct vmx_msr_entry)) ) + if ( total == (PAGE_SIZE / sizeof(*ent)) ) return -ENOSPC; - msr_area_elem = *msr_area + *msr_count; - msr_area_elem->index = msr; - msr_area_elem->mbz = 0; + memmove(ent + 1, ent, sizeof(*ent) * (end - ent)); - ++*msr_count; + ent->index = msr; + ent->mbz = 0; switch ( type ) { case VMX_MSR_HOST: - rdmsrl(msr, msr_area_elem->data); - __vmwrite(VM_EXIT_MSR_LOAD_COUNT, *msr_count); + rdmsrl(msr, ent->data); + __vmwrite(VM_EXIT_MSR_LOAD_COUNT, ++vmx->host_msr_count); break; case VMX_MSR_GUEST: - msr_area_elem->data = 0; - __vmwrite(VM_EXIT_MSR_STORE_COUNT, *msr_count); - __vmwrite(VM_ENTRY_MSR_LOAD_COUNT, *msr_count); + ent->data = 0; + __vmwrite(VM_EXIT_MSR_STORE_COUNT, ++vmx->msr_count); + __vmwrite(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_count); break; } -- generated by git-patchbot for /home/xen/git/xen.git#staging-4.6 _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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