AMD News Archives

Last year AMD issued an advisory around "intermittent system stutter" when engaging the Firmware Trusted Platform Module "fTPM" with newer Ryzen systems running Windows 10 and Windows 11. While at first this only manifested on Windows, with Linux 6.1+ enabling the AMD fTPM RNG by default when present, this system stuttering issue has begun affecting Linux users too.

CVE-2022-27672 is being made public today as the "Cross-Thread Return Address Predictions" bug affecting various AMD and Hygon processors. This vulnerability affects the SMT mode where one sibling thread transitions out of the C0 state and the other sibling thread could use return target predictions.

AMD and Atos announced today that they are building a new supercomputer in Bavaria for the Max Planck Society.

The very promising work around parallel CPU bring-up to speed-up Linux kernel boot times with today's high core count servers and HEDT systems has been revised once more. Notable with the v7 patches is re-enabling support for this time-savings boot feature for AMD processors.

GNU Compiler Collection compiler expert Jan Hubicka at SUSE continues working on last-minute tweaks to the GCC 13 for benefiting AMD's latest Zen 4 processors.

Michał Żygowski of firmware consulting firm 3mdeb presented at FOSDEM 2023 this weekend in Brussels. The focus of Żygowski's presentation for the Free Open-Source Developers' European Meeting was on the current client and server hardware state for AMD platforms with Coreboot / open-source firmware.

Now that we are into February with AMD previously announced the month for learning more about their new Zen 4 processors with 3D V-Cache, this morning they revealed the firm availability dates and pricing.

A new patch series published this week by AMD engineers is preparing Linux kernel support for Secure TSC, a feature found with SEV-SNP enabled processors since the EPYC 7003 "Milan" series.

Merged on Sunday prior to tagging Linux 6.2-rc6 is a late "fix" for the AMD Secure Encrypted Virtualization Secure Nested Paging (SEV-SNP) code to avoid possible situations of undefined behavior with difficult to debug issues where a modern Linux host with SEV-SNP may try booting a Linux virtual machine with an outdated kernel.

Hitting the linux-firmware.git tree this morning were new AMDGPU firmware files for IP blocks found on upcoming hardware. It's likely these new firmware files are for the forthcoming Ryzen 7040 series mobile processors with RDNA3 graphics.

Going back to last August AMD Linux engineers began posting Linux kernel patches for new Quality of Service features coming with Zen 4. After a few rounds of review and updates to those patches, this work enabling the AMD SMBA and BMEC features for 4th Gen EPYC "Genoa" processors appear positioned for introduction in the Linux 6.3 kernel cycle.

Two quality of service features new with the Zen 4 processors are still seeing their software support squared away ahead of mainlining in the Linux kernel.

With AMD Zen 4 processors there is a new Automatic IBRS (Indirect Branch Restricted Speculation) similar to Intel's Enhanced IBRS (eIBRS) functionality for offering lower-overhead Spectre V2 mitigations compared to the Retpoline approach used on Zen 3 and prior. Finally with Linux 6.3 that Auto IBRS support is now set to be merged.

After quietly posting a "request for comments" patch series a few months back to no fanfare, AMD today published their post-RFC patch series today for introducing the AMD CDX bus to the Linux kernel. AMD CDX is ultimately for the interface/bus between the APU and FPGA(s) with future hardware.

SUSE compiler engineer Jan Hubicka has landed some additional AMD Zen 4 "znver4" CPU target tuning ahead of the upcoming GCC 13 stable compiler release.

While the Xilinx Alveo PCIe accelerator cards have been around for several years and there has been ongoing Linux driver work equally as long, one element of the support has remained elusive from the upstream Linux kernel: the XDMA subsystem driver.

Back in December AMD posted P-State Linux driver patches for implementing a "Guided Autononmous Mode" of operation to complement the existing passive mode used by the amd_pstate driver and the pending fully-autonomous/EPP mode that has seen many patch revisions in recent months. While much of AMD's engineering focus has been on getting the P-State EPP code upstreamed, out today is the second iteration of that Guided Autonomous Mode support.

System76 is kicking off the new year by preparing to release a new AMD-powered Linux laptop, an updated Pangolin model.

Since early November AMD has been working on Linux patches for Automatic IBRS. AutoIBRS is a new Zen 4 CPU feature intended to provide better performance than generic Retpolines as part of the Spectre V2 mitigations. Two months later the Linux AutoIBRS patches still haven't been merged yet but up to their sixth revision.

GCC compiler expert Jan Hubicka at SUSE began working on AMD Zen 4 compiler tuning patches that began landing in December for the GCC 13 compiler that will debut as stable in a few months. It looks like the work isn't over on Znver4 tuning with another patch being sent out today for fine-tuning the latest AMD CPU microarchitecture.

For those making use of AMD's Optimizing C/C++/Fortran compilers, ZenNN library, profiling software, and various other CPU-based software resources for EPYC and Ryzen processors, AMD is in the process of rolling out a new area on the website for highlighting these Zen Software Studio assets.

While DragonFlyBSD has previously praised the performance of AMD Ryzen Threadripper CPUs going back to the Zen 2 days, it's taken them until this weekend to get temperature sensor monitoring working for Family 19h processors: Zen 3, Zen 3+, and Zen 4 CPUs.

Following the recent Zen 4 tuning patches that were merged to GCC 13 (Git) just ahead of Christmas, today an AMD patch adding the Zen 4 automatons have been merged ahead of this next open-source compiler release.

Tonight during Lisa Su's keynote for CES 2023, a number of exciting AMD announcements were made.

A change was merged this holiday weekend ahead of Linux 6.2-rc2 that adjusts the default behavior for AMD Ryzen 6000 series "Rembrandt" laptops and newer.

AMD in 2022 continued its open-source/Linux support embrace with offering good launch-day support on both the CPU and GPU sides with their new products, continued ramping up their Linux support on the client side, and has worked more on optimizations and other enhancements to their Linux support.

While the Linux 6.2 kernel merge window just wrapped up, AMD's P-State EPP driver was deemed not ready for making it this cycle. However, with AMD having now iterated it to a ninth revision, it's looking like this P-State "Energy Performance Preference" functionality over the existing P-State driver support will be ready for merging come Linux 6.3.

While AMD provided upstream open-source driver support for the Radeon RX 7900 series launch, the initial user experience can be less than desirable if running a new Radeon GPU but initially running an out-of-date kernel or lacking the necessary firmware support. With a new patch series posted AMD is looking to improve the experience by being able to more easily fallback to the firmware frame-buffer when their AMDGPU kernel graphics driver fails to properly load.

Ahead of the Linux 6.2 merge window ending this weekend, a second batch of the perf subsystem changes have been submitted for this next Linux kernel version. Notable among the various additions to the powerful Linux kernel perf code is handling for various new performance monitoring events with new AMD Zen 4 processors.

Following the basic AMD Zen 4 "znver4" target enablement that was merged for the GCC 13 compiler in October, patches to begin providing tuned support have begun merging for this next GNU Compiler Collection release.

AMD kicked off Christmas week by posting an eighth version of their P-State EPP driver patches for implementing the AMD Energy Performance Preference handling within their recent processors/SoCs for software to hint a performance or energy efficiency hint. P-State EPP can address some of the shortcomings with AMD's original P-State driver implementation merged nearly a year ago and has been showing good results in numbers posted by AMD engineers.

As of today the LLVM Git compiler finally has initial support for AMD Zen 4 CPUs with the -march=znver4 option now wired up for Ryzen 7000 series and EPYC 9004 series processors.

Introduced in early 2021 with now prior-generation AMD EPYC 7003 "Milan" processors was SEV-SNP as the "Secure Nested Paging" addition to their Secure Encrypted Virtualization technology. While this year saw the initial SEV-SNP support was finally merged to the mainline Linux kernel, the hypervisor portion remain outstanding and have taken a step back as the AMD engineers overhauled their implementation.

For those that were holding out hope that the AMD P-State Linux driver's EPP functionality for more power/performance control under Linux would be ready for the Linux 6.2 kernel merge window, it's been rejected for the cycle and will be held off until at least the Linux 6.3 cycle begins in February.

AMD engineers on Thursday released AOMP 16.0-3 as the newest version of their LLVM/Clang downstream focused on providing the latest patches for enjoying AMD Instinct / Radeon OpenMP offloading as part of their ROCm compute stack.

For those running an AMD Ryzen 5000 series "Cezanne" powered laptop, squeezing into the kernel this week ahead of the Linux 6.1 debut on Sunday is a suspend/resume fix affecting various models.

With the AMD P-State CPU frequency scaling driver that has come together over the past year and improved upon there has been the Energy Performance Preference "EPP" mode being worked on recently to further improve the performance/power characteristics of Ryzen and EPYC processors on Linux. A new patch series today implements a third mode for the AMD P-State driver.

Following the initial AMD Zen 4 "znver4" target for GCC 13 that was published and merged in October (and now a SUSE engineer working on providing actually tuned support and accurate cost tables), an initial AMD Zen 4 patch for the LLVM/Clang compiler was published a few days ago.

Back in October AMD sent out their initial Zen 4 "znver4" enablement for the GCC compiler. That initial Zen 4 support was since merged for GCC 13 but that initial enablement carried over the cost tables from Zen 3 and didn't do much in the way of tuning but rather just flipping on the new instructions supported by the Ryzen 7000 series and EPYC 9004 series processors. Today there is finally some juicy tuning patches being sent out for GCC.

While AMD EPYC Genoa launched a few weeks back and the Ryzen 7000 series launched in late September, one of the AMD Zen 4 patch series we are still waiting to arrive for the mainline Linux kernel is the Automatic IBRS enablement.

A little more than a week ago AMD quietly released their Radeon Pro Software for Enterprise Linux 22.Q4 driver, also advertised more recently as the AMD Software: PRO Edition 22.Q4 for Linux driver package. With most Linux enthusiasts and gamers happily using the upstream open-source components in the mainline Linux kernel and Mesa, the new quarterly release slipped under the radar until now.

Back in October the open-source Coreboot firmware project began seeing patches for new AMD SoCs codenamed "Morgana" and "Glinda". That work has continued and over the weekend the "Mayan Morgana" was merged as the reference motherboard for the Morgana SoC.

With the Linux 6.1-rc7 kernel set to be released later today, it will become easier making use of the AMD P-State driver for that enhanced CPU frequency scaling driver intended for Zen 2 and newer EPYC/Ryzen platforms that make use of ACPI CPPC.

After open-sourcing its Radeon Raytracing Analyzer code last week, this week AMD's GPUOpen team has a new open-source project announcement: Brotli-G.

Since the introduction of the AMD P-State driver to the mainline kernel, enthusiasts and gamers have been experimenting with the amd_pstate driver and some distributions like Ubuntu have went with using this driver in place of ACPI CPUFreq by default for Zen 2 and newer processors. Patches posted this week by AMD make it easier to switch between the AMD P-State driver and ACPI CPUFreq.

For going along with the recently merged initial AMD Zen 4 "znver4" support in GCC 13 (in case you missed it, there is further tuning work still ongoing), the Zen 4 support has now been merged to GNU Binutils.

Back in March AMD began sending out patches for PerfMonV2 support with Zen 4 CPUs. This updated AMD Performance Monitoring "V2" code has premiered now with AMD Ryzen 7000 series and AMD EPYC 9004 series processors and the host-side PerfMonV2 code was merged in Linux 5.19. But support for PerfMonV2 within KVM guests has been lacking while now an updated patch series is working to address the functionality there.

Following Znver4 being added to GCC 13 at the end of October albeit a basic implementation, out this week is a follow-up patch to begin making more adaptations to the AMD Zen 4 target.

In addition to AMD this week having released the AMD Optimizing C/C++ Compiler "AOCC" 4.0 as their LLVM/Clang downstream now with various optimizations for Zen 4, the company also released AOMP 16.0-2 as the newest version of their other LLVM/Clang downstream... AOMP is their downstream LLVM/Clang compiler focused on providing the latest Radeon OpenMP GPU offloading support.

Back in September AMD posted the Linux driver patches for P-State EPP as their latest effort to improve the power efficiency of Ryzen and EPYC processors. Sent out this week is now the fourth iteration of those CPU frequency scaling driver patches.