This patchset adds support for the Virtual VMLOAD VMSAVE feature. This feature allows the VMLOAD and VMSAVE instructions to be executed in the Guest mode and not require a #VMEXIT. The value in the RAX for VMLOAD and VMSAVE is treated as a guest physical address and is translated to the host physical address and then the instruction does its normal operation. This feature is enabled by setting bit 1 at position B8h in the VMCB. This bit is set only if the hypervisor has nested paging enabled, is in 64-bit mode and has support for the Virtual VMLOAD VMSAVE feature. Any page faults during this will result in a normal #VMEXIT with nested page fault as the exit code. The advantage of this feature will be the greatly reduced number of world switches to support the VMLOAD and VMSAVE instructions by the outermost hypervisor at Current Privilege Level (CPL) 0. This has been tested with Xen, Hyper-V and KVM as the nested hypervisors. v1->v2: * Added module parameter for Virtual VMLOAD VMSAVE and set its default state to TRUE. Janakarajan Natarajan (4): KVM: SVM: Prepare for new bit definition in lbr_ctl KVM: SVM: Rename lbr_ctl field in the vmcb control area KVM: SVM: Add Virtual VMLOAD VMSAVE feature definition KVM: SVM: Enable Virtual VMLOAD VMSAVE feature arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/svm.h | 5 ++++- arch/x86/kvm/svm.c | 34 +++++++++++++++++++++++++++++----- 3 files changed, 34 insertions(+), 6 deletions(-) -- 2.7.4
