| Message ID | cover.1622019133.git.sidcha@amazon.de (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add support for XMM fast hypercalls | expand |
On Wed, May 26, 2021 at 10:56:07AM +0200, Siddharth Chandrasekaran wrote: > Hyper-V supports the use of XMM registers to perform fast hypercalls. > This allows guests to take advantage of the improved performance of the > fast hypercall interface even though a hypercall may require more than > (the current maximum of) two general purpose registers. > > The XMM fast hypercall interface uses an additional six XMM registers > (XMM0 to XMM5) to allow the caller to pass an input parameter block of > up to 112 bytes. Hyper-V can also return data back to the guest in the > remaining XMM registers that are not used by the current hypercall. > > Although the Hyper-v TLFS mentions that a guest cannot use this feature > unless the hypervisor advertises support for it, some hypercalls which > we plan on upstreaming in future uses them anyway. This patchset adds > necessary infrastructure for handling input/output via XMM registers and > patches kvm_hv_flush_tlb() to use xmm input arguments. Hi Paolo, Are you expecting more reviews on these patches? Thanks. ~ Sid Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879
On 30/06/21 13:56, Siddharth Chandrasekaran wrote: > On Wed, May 26, 2021 at 10:56:07AM +0200, Siddharth Chandrasekaran wrote: >> Hyper-V supports the use of XMM registers to perform fast hypercalls. >> This allows guests to take advantage of the improved performance of the >> fast hypercall interface even though a hypercall may require more than >> (the current maximum of) two general purpose registers. >> >> The XMM fast hypercall interface uses an additional six XMM registers >> (XMM0 to XMM5) to allow the caller to pass an input parameter block of >> up to 112 bytes. Hyper-V can also return data back to the guest in the >> remaining XMM registers that are not used by the current hypercall. >> >> Although the Hyper-v TLFS mentions that a guest cannot use this feature >> unless the hypervisor advertises support for it, some hypercalls which >> we plan on upstreaming in future uses them anyway. This patchset adds >> necessary infrastructure for handling input/output via XMM registers and >> patches kvm_hv_flush_tlb() to use xmm input arguments. > > Hi Paolo, > > Are you expecting more reviews on these patches? They are part of 5.14 already. :) Paolo
On Tue, Jul 06, 2021 at 05:04:59PM +0200, Paolo Bonzini wrote: > On 30/06/21 13:56, Siddharth Chandrasekaran wrote: > > On Wed, May 26, 2021 at 10:56:07AM +0200, Siddharth Chandrasekaran wrote: > > > Hyper-V supports the use of XMM registers to perform fast hypercalls. > > > This allows guests to take advantage of the improved performance of the > > > fast hypercall interface even though a hypercall may require more than > > > (the current maximum of) two general purpose registers. > > > > > > The XMM fast hypercall interface uses an additional six XMM registers > > > (XMM0 to XMM5) to allow the caller to pass an input parameter block of > > > up to 112 bytes. Hyper-V can also return data back to the guest in the > > > remaining XMM registers that are not used by the current hypercall. > > > > > > Although the Hyper-v TLFS mentions that a guest cannot use this feature > > > unless the hypervisor advertises support for it, some hypercalls which > > > we plan on upstreaming in future uses them anyway. This patchset adds > > > necessary infrastructure for handling input/output via XMM registers and > > > patches kvm_hv_flush_tlb() to use xmm input arguments. > > > > Hi Paolo, > > > > Are you expecting more reviews on these patches? > > They are part of 5.14 already. :) Ahh, I see them now. I was expecting them to show up in master - that was the confusion. Thanks! :) ~ Sid Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879
On 06/07/21 17:15, Siddharth Chandrasekaran wrote: > On Tue, Jul 06, 2021 at 05:04:59PM +0200, Paolo Bonzini wrote: >> On 30/06/21 13:56, Siddharth Chandrasekaran wrote: >>> On Wed, May 26, 2021 at 10:56:07AM +0200, Siddharth Chandrasekaran wrote: >>>> Hyper-V supports the use of XMM registers to perform fast hypercalls. >>>> This allows guests to take advantage of the improved performance of the >>>> fast hypercall interface even though a hypercall may require more than >>>> (the current maximum of) two general purpose registers. >>>> >>>> The XMM fast hypercall interface uses an additional six XMM registers >>>> (XMM0 to XMM5) to allow the caller to pass an input parameter block of >>>> up to 112 bytes. Hyper-V can also return data back to the guest in the >>>> remaining XMM registers that are not used by the current hypercall. >>>> >>>> Although the Hyper-v TLFS mentions that a guest cannot use this feature >>>> unless the hypervisor advertises support for it, some hypercalls which >>>> we plan on upstreaming in future uses them anyway. This patchset adds >>>> necessary infrastructure for handling input/output via XMM registers and >>>> patches kvm_hv_flush_tlb() to use xmm input arguments. >>> >>> Hi Paolo, >>> >>> Are you expecting more reviews on these patches? >> >> They are part of 5.14 already. :) > > Ahh, I see them now. I was expecting them to show up in master - that was > the confusion. No problem! The patches for the rc period (in your case it was 5.13) go in master, while yours ended up in next (destined for 5.14). I usually update master only after 5.14-rc1 is out. In this case I didn't even have access to kvm.git on the day that Linus pulled your patches into his tree. Paolo
Hyper-V supports the use of XMM registers to perform fast hypercalls. This allows guests to take advantage of the improved performance of the fast hypercall interface even though a hypercall may require more than (the current maximum of) two general purpose registers. The XMM fast hypercall interface uses an additional six XMM registers (XMM0 to XMM5) to allow the caller to pass an input parameter block of up to 112 bytes. Hyper-V can also return data back to the guest in the remaining XMM registers that are not used by the current hypercall. Although the Hyper-v TLFS mentions that a guest cannot use this feature unless the hypervisor advertises support for it, some hypercalls which we plan on upstreaming in future uses them anyway. This patchset adds necessary infrastructure for handling input/output via XMM registers and patches kvm_hv_flush_tlb() to use xmm input arguments. ~ Sid. v3 -> v4: - Rebase to latest master - Remove unused loop variable j v2 -> v3: - Remove inline for kvm_hv_hypercall_{read,write}_xmm() - Fix typo: s/ouput/output/ - Remove sse128_t from kvm_emulate.h - Reword comment to match TLFS wording - Move num XMM registers macro to hyperv-tlfs.h - Stop advertising HV_X64_HYPERCALL_XMM_OUTPUT_AVAILABLE v1 -> v2: - Add hc.fast to is_xmm_fast_hypercall() check - Split CPUID feature bits for input and output Siddharth Chandrasekaran (4): KVM: x86: Move FPU register accessors into fpu.h KVM: hyper-v: Collect hypercall params into struct KVM: x86: kvm_hv_flush_tlb use inputs from XMM registers KVM: hyper-v: Advertise support for fast XMM hypercalls arch/x86/include/asm/hyperv-tlfs.h | 10 +- arch/x86/kvm/emulate.c | 137 +++--------------- arch/x86/kvm/fpu.h | 140 ++++++++++++++++++ arch/x86/kvm/hyperv.c | 222 +++++++++++++++++++---------- arch/x86/kvm/kvm_emulate.h | 3 +- 5 files changed, 310 insertions(+), 202 deletions(-) create mode 100644 arch/x86/kvm/fpu.h