On 2016/1/29 14:32, Ashok Kumar wrote: > Hi, > > On Sat, Jan 23, 2016 at 07:36:41PM +0800, Shannon Zhao wrote: >> > From: Shannon Zhao <shannon.z...@linaro.org> >> > >> > Add NUMA support for machine virt. Tested successfully running a guest >> > Linux kernel with the following patch applied: >> > >> > - [PATCH v9 0/6] arm64, numa: Add numa support for arm64 platforms >> > https://lwn.net/Articles/672329/ >> > - [PATCH v2 0/4] ACPI based NUMA support for ARM64 >> > http://www.spinics.net/lists/linux-acpi/msg61795.html >> > >> > Changes since v3: >> > * based on new kernel driver and device bindings >> > * add ACPI part >> > >> > Changes since v2: >> > * update to use NUMA node property arm,associativity. >> > >> > Changes since v1: >> > Take into account Peter's comments: >> > * rename virt_memory_init to arm_generate_memory_dtb >> > * move arm_generate_memory_dtb to boot.c and make it a common func >> > * use a struct numa_map to generate numa dtb >> > >> > Example qemu command line: >> > qemu-system-aarch64 \ >> > -enable-kvm -smp 4\ >> > -kernel Image \ >> > -m 512 -machine virt,kernel_irqchip=on \ >> > -initrd guestfs.cpio.gz \ >> > -cpu host -nographic \ >> > -numa node,mem=256M,cpus=0-1,nodeid=0 \ >> > -numa node,mem=256M,cpus=2-3,nodeid=1 \ >> > -append "console=ttyAMA0 root=/dev/ram" >> > >> > Shannon Zhao (5): >> > ARM: Virt: Add /distance-map node for NUMA >> > ARM: Virt: Set numa-node-id for CPUs >> > ARM: Add numa-node-id for /memory node >> > include/hw/acpi/acpi-defs: Add GICC Affinity Structure >> > hw/arm/virt-acpi-build: Generate SRAT table >> > >> > hw/arm/boot.c | 29 ++++++++++++++++++++++- >> > hw/arm/virt-acpi-build.c | 58 >> > +++++++++++++++++++++++++++++++++++++++++++++ >> > hw/arm/virt.c | 37 +++++++++++++++++++++++++++++ >> > hw/i386/acpi-build.c | 2 +- >> > include/hw/acpi/acpi-defs.h | 15 +++++++++++- >> > 5 files changed, 138 insertions(+), 3 deletions(-) >> > >> > -- >> > 2.0.4 >> > > Don't we need to populate the NUMA node in the Affinity byte of MPIDR? > Linux uses the Affinity information in MPIDR to build topology which > might go wrong for the guest in this case. > Maybe a non Linux OS might be impacted more? > Ah, yes. It needs to update the MPIDR. But currently QEMU uses the value from KVM when using KVM. It needs to call kvm_set_one_reg to set the MPIDR and I'm not sure if this will affect KVM by looking at following comments: /* * When KVM is in use, PSCI is emulated in-kernel and not by qemu. * Currently KVM has its own idea about MPIDR assignment, so we * override our defaults with what we get from KVM. */
Peter, do you have any suggestion? > distance-map compatible string has been changed from > "numa,distance-map-v1" to "numa-distance-map-v1" Will update this. Thanks, -- Shannon
