Re: [PATCH v2 0/9] i386/cpu: Support APX for KVM
> No problem, I have done a quick pass with "sed" on the patches and reapplied > them. I do ask you to respin the Diamond Rapids series though, on top of > the for-upstream tag of https://gitlab.com/bonzini/qemu (currently going > through CI). > > Applied for 11.0! Thank you! BTW, could you please have a look at this clean up on outdated SPR comments: https://lore.kernel.org/qemu-devel/[email protected]/ I feel it's better to clear SPR comments before DMR touches AMX. Thanks, Zhao
Re: [PATCH v2 0/9] i386/cpu: Support APX for KVM
On 12/11/25 10:16, Zhao Liu wrote: On Thu, Dec 11, 2025 at 09:08:33AM +0100, Paolo Bonzini wrote: Great, thanks! Just one question, should the CPUID feature be "apx" or "apxf" (and therefore CPUID_7_1_EDX_APXF)? I can fix that myself of course. Good point! I didn't realize this. 1) Per APX spec: (APX adds) CPUID Enumeration for APX_F (APX Foundation). 2) And gcc also use apx_f: https://codebrowser.dev/gcc/gcc/config/i386/cpuid.h.html#_M/bit_APX_F 3) ...and we already have "avx512f". So you're right, I should use "apxf" and CPUID_7_1_EDX_APXF. Since APX CPUID appears in several patches, I can respin a new version quickly. No problem, I have done a quick pass with "sed" on the patches and reapplied them. I do ask you to respin the Diamond Rapids series though, on top of the for-upstream tag of https://gitlab.com/bonzini/qemu (currently going through CI). Applied for 11.0! Paolo
Re: [PATCH v2 0/9] i386/cpu: Support APX for KVM
On Thu, Dec 11, 2025 at 09:08:33AM +0100, Paolo Bonzini wrote: > Date: Thu, 11 Dec 2025 09:08:33 +0100 > From: Paolo Bonzini > Subject: Re: [PATCH v2 0/9] i386/cpu: Support APX for KVM > > On 12/11/25 08:09, Zhao Liu wrote: > > Hi, > > > > This series adds APX (Advanced Performance Extensions) support in QEMU > > to enable APX in Guest based on KVM (RFC v1 [1]). > > > > This series is based on CET v5: > > > > https://lore.kernel.org/qemu-devel/[email protected]/ > > > > And you can also find the code here: > > > > https://gitlab.com/zhao.liu/qemu/-/commits/i386-all-for-dmr-v2.1-12-10-2025 > > > > Compared with v1 [2], v2 adds: > > * HMP support ("print" & "info registers"). > > * gdbstub support. > > > > Thanks for your review! > > Great, thanks! Just one question, should the CPUID feature be "apx" or > "apxf" (and therefore CPUID_7_1_EDX_APXF)? I can fix that myself of course. Good point! I didn't realize this. 1) Per APX spec: (APX adds) CPUID Enumeration for APX_F (APX Foundation). 2) And gcc also use apx_f: https://codebrowser.dev/gcc/gcc/config/i386/cpuid.h.html#_M/bit_APX_F 3) ...and we already have "avx512f". So you're right, I should use "apxf" and CPUID_7_1_EDX_APXF. Since APX CPUID appears in several patches, I can respin a new version quickly. Thanks, Zhao
Re: [PATCH v2 0/9] i386/cpu: Support APX for KVM
On 12/11/25 08:09, Zhao Liu wrote: Hi, This series adds APX (Advanced Performance Extensions) support in QEMU to enable APX in Guest based on KVM (RFC v1 [1]). This series is based on CET v5: https://lore.kernel.org/qemu-devel/[email protected]/ And you can also find the code here: https://gitlab.com/zhao.liu/qemu/-/commits/i386-all-for-dmr-v2.1-12-10-2025 Compared with v1 [2], v2 adds: * HMP support ("print" & "info registers"). * gdbstub support. Thanks for your review! Great, thanks! Just one question, should the CPUID feature be "apx" or "apxf" (and therefore CPUID_7_1_EDX_APXF)? I can fix that myself of course. Thanks, Paolo Overview Intel Advanced Performance Extensions (Intel APX) expands the Intel 64 instruction set architecture with access to more registers (16 additional general-purpose registers (GPRs) R16–R31) and adds various new features that improve general-purpose performance. The extensions are designed to provide efficient performance gains across a variety of workloads without significantly increasing silicon area or power consumption of the core. APX spec link (rev.07) is: https://cdrdv2.intel.com/v1/dl/getContent/861610 At QEMU side, the enabling work mainly includes three parts: 1. save/restore/migrate the xstate of APX. * APX xstate is a user xstate, but it reuses MPX xstate area in un-compacted XSAVE buffer. * To address this, QEMU will reject both APX and MPX if their CPUID feature bits are set at the same (in Patch 1). 2. add related CPUIDs support in feature words. 3. debug support, including HMP & gdbstub. Change Log == Changes sicne v1: * Expend current GPR array (CPUX86State.regs) to 32 elements instead of a new array. * HMP support ("print" & "info registers"). * gdbstub support. [1]: KVM RFC: https://lore.kernel.org/kvm/[email protected]/ [2]: QEMU APX v1: https://lore.kernel.org/qemu-devel/[email protected]/ Thanks and Best Regards, Zhao --- Zhao Liu (6): i386/machine: Use VMSTATE_UINTTL_SUB_ARRAY for vmstate of CPUX86State.regs i386/gdbstub: Add APX support for gdbstub i386/cpu-dump: Dump entended GPRs for APX supported guest i386/monitor: Support EGPRs in hmp_print i386/cpu: Support APX CPUIDs i386/cpu: Mark APX xstate as migratable Zide Chen (3): i386/cpu: Add APX EGPRs into xsave area i386/cpu: Cache EGPRs in CPUX86State i386/cpu: Add APX migration support configs/targets/x86_64-softmmu.mak | 2 +- gdb-xml/i386-64bit-apx.xml | 26 +++ include/migration/cpu.h| 4 ++ target/i386/cpu-dump.c | 30 +++-- target/i386/cpu.c | 68 - target/i386/cpu.h | 48 +++-- target/i386/gdbstub.c | 69 +- target/i386/machine.c | 27 +++- target/i386/monitor.c | 16 +++ target/i386/xsave_helper.c | 16 +++ 10 files changed, 293 insertions(+), 13 deletions(-) create mode 100644 gdb-xml/i386-64bit-apx.xml
