[kvm-unit-tests PATCH v4 0/5] arm64: Change the default QEMU CPU type to "max

[kvm-unit-tests PATCH v4 0/5] arm64: Change the default QEMU CPU type to "max

[Jean-Philippe Brucker]

This is v4 of the series that cleans up the configure flags and sets the
default CPU type to "max" on arm64, in order to test the latest Arm
features.

Since v3 [1] I renamed --qemu-cpu to --target-cpu, to prepare for other
VMMs.

[1] https://lore.kernel.org/all/20250325160031.2390504-3-jean-philippe@linaro.org/


Alexandru Elisei (3):
  configure: arm64: Don't display 'aarch64' as the default architecture
  configure: arm/arm64: Display the correct default processor
  arm64: Implement the ./configure --processor option

Jean-Philippe Brucker (2):
  configure: Add --target-cpu option
  arm64: Use -cpu max as the default for TCG

 scripts/mkstandalone.sh |  3 ++-
 arm/run                 | 15 ++++++-----
 riscv/run               |  8 +++---
 configure               | 55 +++++++++++++++++++++++++++++++++++------
 arm/Makefile.arm        |  1 -
 arm/Makefile.common     |  1 +
 6 files changed, 63 insertions(+), 20 deletions(-)

-- 
2.49.0

[kvm-unit-tests PATCH v4 1/5] configure: arm64: Don't display 'aarch64' as the default architecture

[Jean-Philippe Brucker]

From: Alexandru Elisei <alexandru.elisei@arm.com>

--arch=aarch64, intentional or not, has been supported since the initial
arm64 support, commit 39ac3f8494be ("arm64: initial drop"). However,
"aarch64" does not show up in the list of supported architectures, but
it's displayed as the default architecture if doing ./configure --help
on an arm64 machine.

The help text for --arch changes from:

   --arch=ARCH            architecture to compile for (aarch64). ARCH can be one of:
                           arm, arm64, i386, ppc64, riscv32, riscv64, s390x, x86_64

to:

    --arch=ARCH            architecture to compile for (arm64). ARCH can be one of:
                           arm, arm64, i386, ppc64, riscv32, riscv64, s390x, x86_64

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
 configure | 1 +
 1 file changed, 1 insertion(+)

diff --git a/configure b/configure
index 52904d3a..010c68ff 100755
--- a/configure
+++ b/configure
@@ -43,6 +43,7 @@ else
 fi
 
 usage() {
+    [ "$arch" = "aarch64" ] && arch="arm64"
     cat <<-EOF
 	Usage: $0 [options]
 
-- 
2.49.0

[kvm-unit-tests PATCH v4 2/5] configure: arm/arm64: Display the correct default processor

[Jean-Philippe Brucker]

From: Alexandru Elisei <alexandru.elisei@arm.com>

The help text for the --processor option displays the architecture name as
the default processor type. But the default for arm is cortex-a15, and for
arm64 is cortex-a57. Teach configure to display the correct default
processor type for these two architectures.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
 configure | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/configure b/configure
index 010c68ff..b4875ef3 100755
--- a/configure
+++ b/configure
@@ -5,6 +5,24 @@ if [ -z "${BASH_VERSINFO[0]}" ] || [ "${BASH_VERSINFO[0]}" -lt 4 ] ; then
     exit 1
 fi
 
+# Return the default CPU type to compile for
+function get_default_processor()
+{
+    local arch="$1"
+
+    case "$arch" in
+    "arm")
+        echo "cortex-a15"
+        ;;
+    "arm64")
+        echo "cortex-a57"
+        ;;
+    *)
+        echo "$arch"
+        ;;
+    esac
+}
+
 srcdir=$(cd "$(dirname "$0")"; pwd)
 prefix=/usr/local
 cc=gcc
@@ -44,13 +62,14 @@ fi
 
 usage() {
     [ "$arch" = "aarch64" ] && arch="arm64"
+    [ -z "$processor" ] && processor=$(get_default_processor $arch)
     cat <<-EOF
 	Usage: $0 [options]
 
 	Options include:
 	    --arch=ARCH            architecture to compile for ($arch). ARCH can be one of:
 	                           arm, arm64, i386, ppc64, riscv32, riscv64, s390x, x86_64
-	    --processor=PROCESSOR  processor to compile for ($arch)
+	    --processor=PROCESSOR  processor to compile for ($processor)
 	    --target=TARGET        target platform that the tests will be running on (qemu or
 	                           kvmtool, default is qemu) (arm/arm64 only)
 	    --cross-prefix=PREFIX  cross compiler prefix
@@ -326,13 +345,8 @@ if [ "$earlycon" ]; then
     fi
 fi
 
-[ -z "$processor" ] && processor="$arch"
-
-if [ "$processor" = "arm64" ]; then
-    processor="cortex-a57"
-elif [ "$processor" = "arm" ]; then
-    processor="cortex-a15"
-fi
+# $arch will have changed when cross-compiling.
+[ -z "$processor" ] && processor=$(get_default_processor $arch)
 
 if [ "$arch" = "i386" ] || [ "$arch" = "x86_64" ]; then
     testdir=x86
-- 
2.49.0

[kvm-unit-tests PATCH v4 3/5] arm64: Implement the ./configure --processor option

[Jean-Philippe Brucker]

From: Alexandru Elisei <alexandru.elisei@arm.com>

The help text for the ./configure --processor option says:

    --processor=PROCESSOR  processor to compile for (cortex-a57)

but, unlike arm, the build system does not pass a -mcpu argument to the
compiler. Fix it, and bring arm64 at parity with arm.

Note that this introduces a regression, which is also present on arm: if
the --processor argument is something that the compiler doesn't understand,
but qemu does (like 'max'), then compilation fails. This will be fixed in a
following patch; another fix is to specify a CPU model that gcc implements
by using --cflags=-mcpu=<cpu>.

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 arm/Makefile.arm    | 1 -
 arm/Makefile.common | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/arm/Makefile.arm b/arm/Makefile.arm
index 7fd39f3a..d6250b7f 100644
--- a/arm/Makefile.arm
+++ b/arm/Makefile.arm
@@ -12,7 +12,6 @@ $(error Cannot build arm32 tests as EFI apps)
 endif
 
 CFLAGS += $(machine)
-CFLAGS += -mcpu=$(PROCESSOR)
 CFLAGS += -mno-unaligned-access
 
 ifeq ($(TARGET),qemu)
diff --git a/arm/Makefile.common b/arm/Makefile.common
index f828dbe0..a5d97bcf 100644
--- a/arm/Makefile.common
+++ b/arm/Makefile.common
@@ -25,6 +25,7 @@ AUXFLAGS ?= 0x0
 # stack.o relies on frame pointers.
 KEEP_FRAME_POINTER := y
 
+CFLAGS += -mcpu=$(PROCESSOR)
 CFLAGS += -std=gnu99
 CFLAGS += -ffreestanding
 CFLAGS += -O2
-- 
2.49.0

[kvm-unit-tests PATCH v4 4/5] configure: Add --target-cpu option

[Jean-Philippe Brucker]

Add the --target-cpu option to let users set the CPU type to run on.
At the moment --processor allows to set both GCC -mcpu flag and QEMU
-cpu. On Arm we'd like to pass `-cpu max` to QEMU in order to enable all
the TCG features by default, and it could also be nice to let users
modify the CPU capabilities by setting extra -cpu options. Since GCC
-mcpu doesn't accept "max" or "host", separate the compiler and QEMU
arguments.

`--processor` is now exclusively for compiler options, as indicated by
its documentation ("processor to compile for"). So use $TARGET_CPU on
RISC-V as well.

Suggested-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 scripts/mkstandalone.sh |  3 ++-
 arm/run                 | 15 +++++++++------
 riscv/run               |  8 ++++----
 configure               | 27 +++++++++++++++++++++++++++
 4 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/scripts/mkstandalone.sh b/scripts/mkstandalone.sh
index 2318a85f..c4ba81f1 100755
--- a/scripts/mkstandalone.sh
+++ b/scripts/mkstandalone.sh
@@ -42,7 +42,8 @@ generate_test ()
 
 	config_export ARCH
 	config_export ARCH_NAME
-	config_export PROCESSOR
+	config_export TARGET_CPU
+	config_export DEFAULT_QEMU_CPU
 
 	echo "echo BUILD_HEAD=$(cat build-head)"
 
diff --git a/arm/run b/arm/run
index efdd44ce..ef585582 100755
--- a/arm/run
+++ b/arm/run
@@ -8,7 +8,7 @@ if [ -z "$KUT_STANDALONE" ]; then
 	source config.mak
 	source scripts/arch-run.bash
 fi
-processor="$PROCESSOR"
+qemu_cpu="$TARGET_CPU"
 
 if [ "$QEMU" ] && [ -z "$ACCEL" ] &&
    [ "$HOST" = "aarch64" ] && [ "$ARCH" = "arm" ] &&
@@ -37,12 +37,15 @@ if [ "$ACCEL" = "kvm" ]; then
 	fi
 fi
 
-if [ "$ACCEL" = "kvm" ] || [ "$ACCEL" = "hvf" ]; then
-	if [ "$HOST" = "aarch64" ] || [ "$HOST" = "arm" ]; then
-		processor="host"
+if [ -z "$qemu_cpu" ]; then
+	if ( [ "$ACCEL" = "kvm" ] || [ "$ACCEL" = "hvf" ] ) &&
+	   ( [ "$HOST" = "aarch64" ] || [ "$HOST" = "arm" ] ); then
+		qemu_cpu="host"
 		if [ "$ARCH" = "arm" ] && [ "$HOST" = "aarch64" ]; then
-			processor+=",aarch64=off"
+			qemu_cpu+=",aarch64=off"
 		fi
+	else
+		qemu_cpu="$DEFAULT_QEMU_CPU"
 	fi
 fi
 
@@ -71,7 +74,7 @@ if $qemu $M -device '?' | grep -q pci-testdev; then
 fi
 
 A="-accel $ACCEL$ACCEL_PROPS"
-command="$qemu -nodefaults $M $A -cpu $processor $chr_testdev $pci_testdev"
+command="$qemu -nodefaults $M $A -cpu $qemu_cpu $chr_testdev $pci_testdev"
 command+=" -display none -serial stdio"
 command="$(migration_cmd) $(timeout_cmd) $command"
 
diff --git a/riscv/run b/riscv/run
index e2f5a922..2bd42ad8 100755
--- a/riscv/run
+++ b/riscv/run
@@ -11,12 +11,12 @@ fi
 
 # Allow user overrides of some config.mak variables
 mach=$MACHINE_OVERRIDE
-processor=$PROCESSOR_OVERRIDE
+qemu_cpu=$QEMU_CPU_OVERRIDE
 firmware=$FIRMWARE_OVERRIDE
 
-[ "$PROCESSOR" = "$ARCH" ] && PROCESSOR="max"
 : "${mach:=virt}"
-: "${processor:=$PROCESSOR}"
+: "${qemu_cpu:=$TARGET_CPU}"
+: "${qemu_cpu:=$DEFAULT_QEMU_CPU}"
 : "${firmware:=$FIRMWARE}"
 [ "$firmware" ] && firmware="-bios $firmware"
 
@@ -32,7 +32,7 @@ fi
 mach="-machine $mach"
 
 command="$qemu -nodefaults -nographic -serial mon:stdio"
-command+=" $mach $acc $firmware -cpu $processor "
+command+=" $mach $acc $firmware -cpu $qemu_cpu "
 command="$(migration_cmd) $(timeout_cmd) $command"
 
 if [ "$UEFI_SHELL_RUN" = "y" ]; then
diff --git a/configure b/configure
index b4875ef3..63367bbc 100755
--- a/configure
+++ b/configure
@@ -23,6 +23,24 @@ function get_default_processor()
     esac
 }
 
+# Return the default CPU type to run on
+function get_default_qemu_cpu()
+{
+    local arch="$1"
+
+    case "$arch" in
+    "arm")
+        echo "cortex-a15"
+        ;;
+    "arm64")
+        echo "cortex-a57"
+        ;;
+    "riscv32" | "riscv64")
+        echo "max"
+        ;;
+    esac
+}
+
 srcdir=$(cd "$(dirname "$0")"; pwd)
 prefix=/usr/local
 cc=gcc
@@ -52,6 +70,7 @@ earlycon=
 console=
 efi=
 efi_direct=
+target_cpu=
 
 # Enable -Werror by default for git repositories only (i.e. developer builds)
 if [ -e "$srcdir"/.git ]; then
@@ -70,6 +89,9 @@ usage() {
 	    --arch=ARCH            architecture to compile for ($arch). ARCH can be one of:
 	                           arm, arm64, i386, ppc64, riscv32, riscv64, s390x, x86_64
 	    --processor=PROCESSOR  processor to compile for ($processor)
+	    --target-cpu=CPU       the CPU model to run on. If left unset, the run script
+	                           selects the best value based on the host system and the
+	                           test configuration.
 	    --target=TARGET        target platform that the tests will be running on (qemu or
 	                           kvmtool, default is qemu) (arm/arm64 only)
 	    --cross-prefix=PREFIX  cross compiler prefix
@@ -146,6 +168,9 @@ while [[ $optno -le $argc ]]; do
         --processor)
 	    processor="$arg"
 	    ;;
+	--target-cpu)
+	    target_cpu="$arg"
+	    ;;
 	--target)
 	    target="$arg"
 	    ;;
@@ -471,6 +496,8 @@ ARCH=$arch
 ARCH_NAME=$arch_name
 ARCH_LIBDIR=$arch_libdir
 PROCESSOR=$processor
+TARGET_CPU=$target_cpu
+DEFAULT_QEMU_CPU=$(get_default_qemu_cpu $arch)
 CC=$cc
 CFLAGS=$cflags
 LD=$cross_prefix$ld
-- 
2.49.0

[kvm-unit-tests PATCH v4 5/5] arm64: Use -cpu max as the default for TCG

[Jean-Philippe Brucker]

In order to test all the latest features, default to "max" as the QEMU
CPU type on arm64. Leave the default 32-bit CPU as cortex-a15, because
that allows running the 32-bit tests with both qemu-system-arm, and with
qemu-system-aarch64 whose default "max" CPU doesn't boot in 32-bit mode.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 configure | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/configure b/configure
index 63367bbc..20bf5042 100755
--- a/configure
+++ b/configure
@@ -32,10 +32,7 @@ function get_default_qemu_cpu()
     "arm")
         echo "cortex-a15"
         ;;
-    "arm64")
-        echo "cortex-a57"
-        ;;
-    "riscv32" | "riscv64")
+    "arm64" | "riscv32" | "riscv64")
         echo "max"
         ;;
     esac
-- 
2.49.0

Re: [kvm-unit-tests PATCH v4 0/5] arm64: Change the default QEMU CPU type to "max

[Andrew Jones]

On Tue, Apr 08, 2025 at 02:20:49PM +0100, Jean-Philippe Brucker wrote:
> This is v4 of the series that cleans up the configure flags and sets the
> default CPU type to "max" on arm64, in order to test the latest Arm
> features.
> 
> Since v3 [1] I renamed --qemu-cpu to --target-cpu, to prepare for other
> VMMs.
> 
> [1] https://lore.kernel.org/all/20250325160031.2390504-3-jean-philippe@linaro.org/
> 
> 
> Alexandru Elisei (3):
>   configure: arm64: Don't display 'aarch64' as the default architecture
>   configure: arm/arm64: Display the correct default processor
>   arm64: Implement the ./configure --processor option
> 
> Jean-Philippe Brucker (2):
>   configure: Add --target-cpu option
>   arm64: Use -cpu max as the default for TCG
> 
>  scripts/mkstandalone.sh |  3 ++-
>  arm/run                 | 15 ++++++-----
>  riscv/run               |  8 +++---
>  configure               | 55 +++++++++++++++++++++++++++++++++++------
>  arm/Makefile.arm        |  1 -
>  arm/Makefile.common     |  1 +
>  6 files changed, 63 insertions(+), 20 deletions(-)
> 
> -- 
> 2.49.0
>

Merged through arm/queue.

Thanks,
drew