| Message ID | 20210426111333.967729-1-mlevitsk@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Introduce KVM_{GET|SET}_SREGS2 and fix PDPTR migration | expand |
On Mon, Apr 26, 2021, Maxim Levitsky wrote: > This patch set aims to fix few flaws that were discovered > in KVM_{GET|SET}_SREGS on x86: > > * There is no support for reading/writing PDPTRs although > these are considered to be part of the guest state. > > * There is useless interrupt bitmap which isn't needed > > * No support for future extensions (via flags and such) > > Also if the user doesn't use the new SREG2 api, the PDPTR > load after migration is now done on KVM_REQ_GET_NESTED_STATE_PAGES > to at least read them correctly in cases when guest memory > map is not up to date when nested state is loaded. > > This patch series was tested by doing nested migration test > of 32 bit PAE L1 + 32 bit PAE L2 on AMD and Intel and by > nested migration test of 64 bit L1 + 32 bit PAE L2 on AMD. > The later test currently fails on Intel (regardless of my patches). > > Changes from V1: > - move only PDPTRS load to KVM_REQ_GET_NESTED_STATE_PAGES on VMX > - rebase on top of kvm/queue > - improve the KVM_GET_SREGS2 to have flag for PDPTRS > and remove padding > > Patches to qemu will be send soon as well. How did you want to handle integration with the removal of pdptrs_changed()? https://lkml.kernel.org/r/68ff1249-2902-43d5-3dfd-35b1f14c4f90@redhat.com
On Wed, 2021-05-26 at 18:01 +0000, Sean Christopherson wrote: > On Mon, Apr 26, 2021, Maxim Levitsky wrote: > > This patch set aims to fix few flaws that were discovered > > in KVM_{GET|SET}_SREGS on x86: > > > > * There is no support for reading/writing PDPTRs although > > these are considered to be part of the guest state. > > > > * There is useless interrupt bitmap which isn't needed > > > > * No support for future extensions (via flags and such) > > > > Also if the user doesn't use the new SREG2 api, the PDPTR > > load after migration is now done on KVM_REQ_GET_NESTED_STATE_PAGES > > to at least read them correctly in cases when guest memory > > map is not up to date when nested state is loaded. > > > > This patch series was tested by doing nested migration test > > of 32 bit PAE L1 + 32 bit PAE L2 on AMD and Intel and by > > nested migration test of 64 bit L1 + 32 bit PAE L2 on AMD. > > The later test currently fails on Intel (regardless of my patches). > > > > Changes from V1: > > - move only PDPTRS load to KVM_REQ_GET_NESTED_STATE_PAGES on VMX > > - rebase on top of kvm/queue > > - improve the KVM_GET_SREGS2 to have flag for PDPTRS > > and remove padding > > > > Patches to qemu will be send soon as well. > > How did you want to handle integration with the removal of > pdptrs_changed()? > > https://lkml.kernel.org/r/68ff1249-2902-43d5-3dfd-35b1f14c4f90@redhat.com > Hi! Sorry that I missed your mail. I will take a look in a day or so at this, and I don't envision any significant trouble with removal of pdptrs_changed, since it is only an optimization anyway. Thanks, Best regards, Maxim Levitsky
This patch set aims to fix few flaws that were discovered in KVM_{GET|SET}_SREGS on x86: * There is no support for reading/writing PDPTRs although these are considered to be part of the guest state. * There is useless interrupt bitmap which isn't needed * No support for future extensions (via flags and such) Also if the user doesn't use the new SREG2 api, the PDPTR load after migration is now done on KVM_REQ_GET_NESTED_STATE_PAGES to at least read them correctly in cases when guest memory map is not up to date when nested state is loaded. This patch series was tested by doing nested migration test of 32 bit PAE L1 + 32 bit PAE L2 on AMD and Intel and by nested migration test of 64 bit L1 + 32 bit PAE L2 on AMD. The later test currently fails on Intel (regardless of my patches). Changes from V1: - move only PDPTRS load to KVM_REQ_GET_NESTED_STATE_PAGES on VMX - rebase on top of kvm/queue - improve the KVM_GET_SREGS2 to have flag for PDPTRS and remove padding Patches to qemu will be send soon as well. Best regards, Maxim Levitskky Maxim Levitsky (6): KVM: nSVM: refactor the CR3 reload on migration KVM: nVMX: delay loading of PDPTRs to KVM_REQ_GET_NESTED_STATE_PAGES KVM: x86: introduce kvm_register_clear_available KVM: x86: Introduce KVM_GET_SREGS2 / KVM_SET_SREGS2 KVM: nSVM: avoid loading PDPTRs after migration when possible KVM: nVMX: avoid loading PDPTRs after migration when possible Documentation/virt/kvm/api.rst | 48 +++++++++++ arch/x86/include/asm/kvm_host.h | 7 ++ arch/x86/include/uapi/asm/kvm.h | 13 +++ arch/x86/kvm/kvm_cache_regs.h | 12 +++ arch/x86/kvm/svm/nested.c | 33 ++++++-- arch/x86/kvm/svm/svm.c | 6 +- arch/x86/kvm/vmx/nested.c | 24 ++++-- arch/x86/kvm/x86.c | 139 ++++++++++++++++++++++++++------ include/uapi/linux/kvm.h | 4 + 9 files changed, 246 insertions(+), 40 deletions(-)