Hi Sean, Paolo, Following up from previous v3 discussion: https://lore.kernel.org/kvm/X%2FSfw15OWarseivB@xxxxxxxxxx/ I got bit in internal testing by a bug in v3 of this series that Sean had already pointed out in v3 comments, so I thought it might be good to go ahead and send a v4 with those fixes included. I also saw that Sean's vmsave helpers are now in kvm/queue, so I've rebased these on top of those, and made use of the new vmsave/vmload helpers: https://lore.kernel.org/kvm/8880fedc-14aa-1f14-b87b-118ebe0932a2@xxxxxxxxxx/ Thanks! -Mike = Overview = This series re-works the SVM KVM implementation to use vmload/vmsave to handle saving/restoring additional host MSRs rather than explicit MSR read/writes, resulting in a significant performance improvement for some specific workloads and simplifying some of the save/load code (PATCH 1). With those changes some commonalities emerge between SEV-ES and normal vcpu_load/vcpu_put paths, which we then take advantage of to share more code, as well as refactor them in a way that more closely aligns with the VMX implementation (PATCH 2 and 3). v4: - rebased on kvm/queue - use sme_page_pa() when accessing save area (Sean) - make sure vmload during host reboot is handled (Sean) - introduce vmload() helper like we have with vmsave(), use that instead of moving the introduce to ASM (Sean) v3: - rebased on kvm-next - remove uneeded braces from host MSR save/load loops (Sean) - use page_to_phys() in place of page_to_pfn() and shifting (Sean) - use stack instead of struct field to cache host save area outside of per-cpu storage, and pass as an argument to __svm_vcpu_run() to handle the VMLOAD in ASM code rather than inlining ASM (Sean/Andy) - remove now-uneeded index/sev_es_restored fields from host_save_user_msrs list - move host-saving/guest-loading of registers to prepare_guest_switch(), and host-loading of registers to prepare_host_switch, for both normal and sev-es paths (Sean) v2: - rebase on latest kvm/next - move VMLOAD to just after vmexit so we can use it to handle all FS/GS host state restoration and rather than relying on loadsegment() and explicit write to MSR_GS_BASE (Andy) - drop 'host' field from struct vcpu_svm since it is no longer needed for storing FS/GS/LDT state (Andy) arch/x86/kvm/svm/sev.c | 30 +----------------------------- arch/x86/kvm/svm/svm.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------------------------------------- arch/x86/kvm/svm/svm.h | 29 +++++------------------------ arch/x86/kvm/svm/svm_ops.h | 5 +++++ 4 files changed, 67 insertions(+), 104 deletions(-)
