Re: [Qemu-devel] [kvm-unit-tests PATCH v5 03/11] arm/arm64: smp: support more than 8 cpus

[Andre Przywara]

Hi,

On 10/11/16 17:21, Andrew Jones wrote:
> By adding support for launching with gicv3 we can break the 8 vcpu
> limit. This patch adds support to smp code and also selects the
> vgic model corresponding to the host. The vgic model may also be
> manually selected by adding e.g. -machine gic-version=3 to
> extra_params.
> 
> Reviewed-by: Alex Bennée 
> Signed-off-by: Andrew Jones 
> 
> ---
> v5: left cpus a u32 for now. Changing to u64 requires a change to
> devicetree. Will do it later. [Andre]

Given that we address this in the future:

Reviewed-by: Andre Przywara 

[Qemu-devel] [kvm-unit-tests PATCH v5 03/11] arm/arm64: smp: support more than 8 cpus

[Andrew Jones]

By adding support for launching with gicv3 we can break the 8 vcpu
limit. This patch adds support to smp code and also selects the
vgic model corresponding to the host. The vgic model may also be
manually selected by adding e.g. -machine gic-version=3 to
extra_params.

Reviewed-by: Alex Bennée 
Signed-off-by: Andrew Jones 

---
v5: left cpus a u32 for now. Changing to u64 requires a change to
devicetree. Will do it later. [Andre]
v4: improved commit message
---
 arm/run   | 19 ---
 arm/selftest.c|  5 -
 lib/arm/asm/processor.h   |  9 +++--
 lib/arm/asm/setup.h   |  4 ++--
 lib/arm/setup.c   | 10 ++
 lib/arm64/asm/processor.h |  9 +++--
 6 files changed, 42 insertions(+), 14 deletions(-)

diff --git a/arm/run b/arm/run
index a2f35ef6a7e6..2d0698619606 100755
--- a/arm/run
+++ b/arm/run
@@ -31,13 +31,6 @@ if [ -z "$ACCEL" ]; then
fi
 fi
 
-if [ "$HOST" = "aarch64" ] && [ "$ACCEL" = "kvm" ]; then
-   processor="host"
-   if [ "$ARCH" = "arm" ]; then
-   processor+=",aarch64=off"
-   fi
-fi
-
 qemu="${QEMU:-qemu-system-$ARCH_NAME}"
 qpath=$(which $qemu 2>/dev/null)
 
@@ -53,6 +46,18 @@ fi
 
 M='-machine virt'
 
+if [ "$ACCEL" = "kvm" ]; then
+   if $qemu $M,\? 2>&1 | grep gic-version > /dev/null; then
+   M+=',gic-version=host'
+   fi
+   if [ "$HOST" = "aarch64" ]; then
+   processor="host"
+   if [ "$ARCH" = "arm" ]; then
+   processor+=",aarch64=off"
+   fi
+   fi
+fi
+
 if ! $qemu $M -device '?' 2>&1 | grep virtconsole > /dev/null; then
echo "$qpath doesn't support virtio-console for chr-testdev. Exiting."
exit 2
diff --git a/arm/selftest.c b/arm/selftest.c
index 196164f5313d..2f117f795d2d 100644
--- a/arm/selftest.c
+++ b/arm/selftest.c
@@ -312,9 +312,10 @@ static bool psci_check(void)
 static cpumask_t smp_reported;
 static void cpu_report(void)
 {
+   unsigned long mpidr = get_mpidr();
int cpu = smp_processor_id();
 
-   report("CPU%d online", true, cpu);
+   report("CPU(%3d) mpidr=%lx", mpidr_to_cpu(mpidr) == cpu, cpu, mpidr);
cpumask_set_cpu(cpu, _reported);
halt();
 }
@@ -343,6 +344,7 @@ int main(int argc, char **argv)
 
} else if (strcmp(argv[1], "smp") == 0) {
 
+   unsigned long mpidr = get_mpidr();
int cpu;
 
report("PSCI version", psci_check());
@@ -353,6 +355,7 @@ int main(int argc, char **argv)
smp_boot_secondary(cpu, cpu_report);
}
 
+   report("CPU(%3d) mpidr=%lx", mpidr_to_cpu(mpidr) == 0, 0, 
mpidr);
cpumask_set_cpu(0, _reported);
while (!cpumask_full(_reported))
cpu_relax();
diff --git a/lib/arm/asm/processor.h b/lib/arm/asm/processor.h
index 02f912f99974..ecf5bbe1824a 100644
--- a/lib/arm/asm/processor.h
+++ b/lib/arm/asm/processor.h
@@ -40,8 +40,13 @@ static inline unsigned long get_mpidr(void)
return mpidr;
 }
 
-/* Only support Aff0 for now, up to 4 cpus */
-#define mpidr_to_cpu(mpidr) ((int)((mpidr) & 0xff))
+#define MPIDR_HWID_BITMASK 0xff
+extern int mpidr_to_cpu(unsigned long mpidr);
+
+#define MPIDR_LEVEL_SHIFT(level) \
+   (((1 << level) >> 1) << 3)
+#define MPIDR_AFFINITY_LEVEL(mpidr, level) \
+   ((mpidr >> MPIDR_LEVEL_SHIFT(level)) & 0xff)
 
 extern void start_usr(void (*func)(void *arg), void *arg, unsigned long 
sp_usr);
 extern bool is_user(void);
diff --git a/lib/arm/asm/setup.h b/lib/arm/asm/setup.h
index cb8fdbd38dd5..1de99dd184d1 100644
--- a/lib/arm/asm/setup.h
+++ b/lib/arm/asm/setup.h
@@ -10,8 +10,8 @@
 #include 
 #include 
 
-#define NR_CPUS8
-extern u32 cpus[NR_CPUS];
+#define NR_CPUS255
+extern u32 cpus[NR_CPUS];  /* per-cpu IDs (MPIDRs) */
 extern int nr_cpus;
 
 #define NR_MEM_REGIONS 8
diff --git a/lib/arm/setup.c b/lib/arm/setup.c
index 7e7b39f11dde..241bf9410447 100644
--- a/lib/arm/setup.c
+++ b/lib/arm/setup.c
@@ -30,6 +30,16 @@ int nr_cpus;
 struct mem_region mem_regions[NR_MEM_REGIONS];
 phys_addr_t __phys_offset, __phys_end;
 
+int mpidr_to_cpu(unsigned long mpidr)
+{
+   int i;
+
+   for (i = 0; i < nr_cpus; ++i)
+   if (cpus[i] == (mpidr & MPIDR_HWID_BITMASK))
+   return i;
+   return -1;
+}
+
 static void cpu_set(int fdtnode __unused, u32 regval, void *info __unused)
 {
int cpu = nr_cpus++;
diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h
index 9a208ff729b7..7e448dc81a6a 100644
--- a/lib/arm64/asm/processor.h
+++ b/lib/arm64/asm/processor.h
@@ -78,8 +78,13 @@ static inline type get_##reg(void)   
\
 
 DEFINE_GET_SYSREG64(mpidr)
 
-/* Only support Aff0 for now, gicv2 only */
-#define mpidr_to_cpu(mpidr) ((int)((mpidr) & 0xff))
+#define