On Thu, Feb 20, 2025 at 3:50 PM Michael S. Tsirkin <m...@redhat.com> wrote: > > On Fri, Dec 13, 2024 at 05:26:37PM +0000, Hendrik Wuethrich wrote: > > From: Hendrik Wüthrich <whend...@google.com> > > > > The aim of this patch series is to emulate Intel RDT features in order > > to make testing of the linux Resctrl subsystem possible with Qemu. > > > > A branch with the patches applied can be found at: > > https://github.com/Gray-Colors/Intel_RDT_patches_applied/tree/rdt_v5 > > > > The changes made introduce the following features: > > > > There was just my minor comment, are you going to post v6?
I found out about some larger issues, mostly in the mapping of RDT state to cores, and am rewriting some parts (mostly of the rdt.c file). I hope to be able to send something out in the coming week. > > > * Feature enumeration for Intel RDT allocation. > > * Feature enumeration for Intel RDT monitoring. > > * Intel RDT monitoring system interface. > > * Intel RDT allocation system interface. > > > > By adding these features, a barebones implementation most of the RDT > > state and MSRs is introduced, which can be enabled through qemu > > command line flags. > > The features missing for a faithful recreation of RDT are CDP and > > non-linear MBA throttle, as well as the possibility to configure > > various values through the command line, as some properties can be > > different across different machines. For increased ease of use, the > > correct features should be automatically enabled on machines that > > support RDT functionality. > > The missing features mentioned above will be implemented in the > > following order: > > > > * Expand feature set for RDT allocation to include CDP and non-linear > > MBA throttle > > * Allow for command line configuration of some values, such as the L3 > > CBM length > > * Automatically enable RDT on machines that officially support it. > > > > Will NOT be implemented > > * Tests to simulate interaction with the host by the guest > > > > Command line examples assuming entire patch series is applied (This > > requires a kernel with Resctrl enabled): > > > > To emulate Intel RDT features: > > > > Currently, it is necessary to force the RDT options on in qemu, as it is > > not automatically enabled for any machines. An example would be the > > following: > > -cpu Skylake-Server,+l3-cmt,+rdt-m,+rdt-a,+mba,+l3-cat,+l2-cat > > and > > -device rdt > > > > Just enabling RDT in qemu won't really help, though. The following > > option allows resctrl in the kernel: > > - Kernel options: rdt=mbmlocal,mbmtotal,cmt,mba,l2cat,l3cat > > > > To use Resctrl in the Qemu, please refer to: > > https://docs.kernel.org/arch/x86/resctrl.html > > > > V4 -> V5 > > - rebase > > - fix feature bit names to all be in hex > > > > Hendrik Wüthrich (8): > > i386: Add Intel RDT device and State to config. > > i386: Add init and realize functionality for RDT device. > > i386: Add RDT functionality > > i386: Add RDT device interface through MSRs > > i386: Add CPUID enumeration for RDT > > i386: Add RDT feature flags. > > i386/cpu: Adjust CPUID level for RDT features > > i386/cpu: Adjust level for RDT on full_cpuid_auto_level > > > > hw/i386/Kconfig | 4 + > > hw/i386/meson.build | 1 + > > hw/i386/rdt.c | 286 +++++++++++++++++++++++++++ > > include/hw/i386/rdt.h | 76 +++++++ > > target/i386/cpu.c | 114 ++++++++++- > > target/i386/cpu.h | 24 +++ > > target/i386/tcg/sysemu/misc_helper.c | 81 ++++++++ > > 7 files changed, 584 insertions(+), 2 deletions(-) > > create mode 100644 hw/i386/rdt.c > > create mode 100644 include/hw/i386/rdt.h > > > > -- > > 2.47.1.613.gc27f4b7a9f-goog >
