| Message ID | 20240704112511.184257-1-ewanhai-oc@zhaoxin.com |
|---|---|
| Headers | show |
| Series | Add support for Zhaoxin Yongfeng CPU model and other improvements | expand |
Dear Maintainers, Could you please review the current patchset and let me know if you have any concerns? On 7/4/24 07:25, EwanHai wrote: > ### Summary of changes > > EwanHai (4): > target/i386: Add support for Zhaoxin CPU vendor identification > target/i386: Add CPUID leaf 0xC000_0001 EDX definitions > target/i386: Introduce Zhaoxin Yongfeng CPU model > target/i386: Update CMPLegacy handling for Zhaoxin CPUs > > target/i386/cpu.c | 128 ++++++++++++++++++++++++++++++++++++++++++++-- > target/i386/cpu.h | 41 ++++++++++++++- > 2 files changed, 165 insertions(+), 4 deletions(-) > > ### Changes since v1 > 1. Removed VIA-related information from the patch description to avoid > misunderstanding. > 2. Replaced CPUID_VENDOR_VIA with CPUID_VENDOR_ZHAOXIN1 because the > "Centaurhauls" vendor ID now belongs to Zhaoxin.The previous CPUID_VENDOR_VIA > macro was only defined but never used in QEMU, making this change > straightforward. > > v1 link: https://lore.kernel.org/qemu-devel/20240625091905.1325205-1-ewanhai- > oc@zhaoxin.com/ > > ### Known Issues > 1. Issue with VMX Preemption Timer Rate on Yongfeng CPU: > - Description: On Yongfeng CPUs, the VMX preemption timer rate is 128, > meaning that bits 4:0 of MSR_IA32_VMX_MISC_CTLS should be set to 7. > However, due to Intel's rate being 5, the Linux kernel has hardcoded > this value as 5: `#define VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE 5`. > - Impact: This discrepancy can cause incorrect behavior in the VMX > preemption timer on Yongfeng CPUs. > - Workaround: A patch to correct this issue in the Linux kernel is > currently being prepared and will be submitted soon.
### Summary of changes EwanHai (4): target/i386: Add support for Zhaoxin CPU vendor identification target/i386: Add CPUID leaf 0xC000_0001 EDX definitions target/i386: Introduce Zhaoxin Yongfeng CPU model target/i386: Update CMPLegacy handling for Zhaoxin CPUs target/i386/cpu.c | 128 ++++++++++++++++++++++++++++++++++++++++++++-- target/i386/cpu.h | 41 ++++++++++++++- 2 files changed, 165 insertions(+), 4 deletions(-) ### Changes since v1 1. Removed VIA-related information from the patch description to avoid misunderstanding. 2. Replaced CPUID_VENDOR_VIA with CPUID_VENDOR_ZHAOXIN1 because the "Centaurhauls" vendor ID now belongs to Zhaoxin.The previous CPUID_VENDOR_VIA macro was only defined but never used in QEMU, making this change straightforward. v1 link: https://lore.kernel.org/qemu-devel/20240625091905.1325205-1-ewanhai- oc@zhaoxin.com/ ### Known Issues 1. Issue with VMX Preemption Timer Rate on Yongfeng CPU: - Description: On Yongfeng CPUs, the VMX preemption timer rate is 128, meaning that bits 4:0 of MSR_IA32_VMX_MISC_CTLS should be set to 7. However, due to Intel's rate being 5, the Linux kernel has hardcoded this value as 5: `#define VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE 5`. - Impact: This discrepancy can cause incorrect behavior in the VMX preemption timer on Yongfeng CPUs. - Workaround: A patch to correct this issue in the Linux kernel is currently being prepared and will be submitted soon.