From ee4336f9470b74f4dd3493d1fdbd61ff13005f9d Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 26 Apr 2024 13:29:11 +0100 Subject: hw/arm/sbsa-ref: Force CPU generic timer to 62.5MHz MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently QEMU CPUs always run with a generic timer counter frequency of 62.5MHz, but ARMv8.6 CPUs will run at 1GHz. For older versions of the TF-A firmware that sbsa-ref runs, the frequency of the generic timer is hardcoded into the firmware, and so if the CPU actually has a different frequency then timers in the guest will be set incorrectly. The default frequency used by the 'max' CPU is about to change, so make the sbsa-ref board force the CPU frequency to the value which the firmware expects. Newer versions of TF-A will read the frequency from the CPU's CNTFRQ_EL0 register: https://github.com/ARM-software/arm-trusted-firmware/commit/4c77fac98dac0bebc63798aae9101ac865b87148 so in the longer term we could make this board use the 1GHz frequency. We will need to make sure we update the binaries used by our avocado test Aarch64SbsarefMachine.test_sbsaref_alpine_linux_max_pauth_impdef before we can do that. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Marcin Juszkiewicz Message-id: 20240426122913.3427983-3-peter.maydell@linaro.org --- hw/arm/sbsa-ref.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'hw/arm') diff --git a/hw/arm/sbsa-ref.c b/hw/arm/sbsa-ref.c index f5709d6..36f6f71 100644 --- a/hw/arm/sbsa-ref.c +++ b/hw/arm/sbsa-ref.c @@ -60,6 +60,19 @@ #define NUM_SMMU_IRQS 4 #define NUM_SATA_PORTS 6 +/* + * Generic timer frequency in Hz (which drives both the CPU generic timers + * and the SBSA watchdog-timer). Older versions of the TF-A firmware + * typically used with sbsa-ref (including the binaries in our Avocado test + * Aarch64SbsarefMachine.test_sbsaref_alpine_linux_max_pauth_impdef + * assume it is this value. + * + * TODO: this value is not architecturally correct for an Armv8.6 or + * better CPU, so we should move to 1GHz once the TF-A fix above has + * made it into a release and into our Avocado test. + */ +#define SBSA_GTIMER_HZ 62500000 + enum { SBSA_FLASH, SBSA_MEM, @@ -767,6 +780,8 @@ static void sbsa_ref_init(MachineState *machine) &error_abort); } + object_property_set_int(cpuobj, "cntfrq", SBSA_GTIMER_HZ, &error_abort); + object_property_set_link(cpuobj, "memory", OBJECT(sysmem), &error_abort); -- cgit v1.1