On 2/5/19 12:38 PM, Andrew Jones wrote:
> On Tue, Feb 05, 2019 at 12:05:35PM +0000, Alexandru Elisei wrote:
>> On 2/4/19 2:39 PM, Andrew Jones wrote:
>>> On Mon, Feb 04, 2019 at 01:44:07PM +0000, Alexandru Elisei wrote:
>>>> kvm-unit-tests is designed to be run with QEMU as the virtual machine
>>>> monitor. It relies on devices emulated by QEMU (like isa-debug-exit or
>>>> testdev) and it makes certain assumptions based on the implicit QEMU
>>>> virtual environment configuration (like the serial base address).
>>>>
>>>> kvmtool [1] is a lightweight virtual machine monitor for running KVM
>>>> guests. kvmtool has reduced complexity compared to QEMU and is easily
>>>> hackable.
>>>>
>>>> This patch series aims to make it possible to run kvm-unit-tests using
>>>> kvmtool on the arm and arm64 architectures, with two caveats:
>>>>
>>>> (1) When terminating a test, the userspace process won't exit with an exit
>>>> code that signals the success or failure of the test. Output from the test
>>>> can still be parsed to determine the outcome of the test.
>>>>
>>>> (2) kvmtool has been designed to work with a linux guest and it
>>>> automatically generates the command line arguments for a Linux kernel. The
>>>> arm/arm64 selftest and gic tests will fail if unexpected command line
>>>> arguments are found. To get around this limitation, the test binary needs
>>>> to be loaded using the --firmware option introduced by kvmtool in commit
>>>> 5e4b563d75b9 ("arm: Allow command line for firmware"). This option
>>>> suppresses the automatic kernel command line and can be used to run all
>>>> tests, not just the tests that require specific arguments.
>>>>
>>>> The run scripts haven't been modified. To run a test under kvmtool, one
>>>> needs to launch kvmtool manually. For example, to run the timer test the
>>>> following command can be used:
>>>>
>>>> lkvm run --cpus 1 --console serial --firmware timer.flat.
>>>>
>>>> To run the gicv3-ipi test:
>>>>
>>>> lkvm run --cpus 8 --console serial --params "ipi" --irqchip gicv3 \
>>>> --firmware gic.flat
>>> This looks good to me. I tested with lkvm and saw that all tests were able
>>> to run and pass, except pci-test since lkvm doesn't have pci-testdev. The
>>> only other issue was selftest.vectors-user which ends in user mode and
>>> thus can't make the PSCI call to exit. The following patch can get that
>>> to work if lkvm users want it
>>>
>>> diff --git a/arm/selftest.c b/arm/selftest.c
>>> index ea5101ef7217..7ba3f02a9b9d 100644
>>> --- a/arm/selftest.c
>>> +++ b/arm/selftest.c
>>> @@ -272,10 +272,18 @@ static bool check_svc(void)
>>> }
>>> #endif
>>>
>>> +static void user_psci_off(struct pt_regs *regs, unsigned int esr)
>>> +{
>>> + psci_system_off();
>> I was wondering if it's worth checking that the cause for the unknown exception
>> was actually the instruction hvc #0 from user space. Getting the function id
>> from x0/r0 is trivial, and we could also check the opcode from the memory
>> location pointed to by the pc.
>>> + halt();
>>> +}
>>> +
>>> static void check_vectors(void *arg __unused)
>>> {
>>> report("und", check_und());
>>> report("svc", check_svc());
>>> + if (is_user())
>>> + install_exception_handler(EL0_SYNC_64, ESR_EL1_EC_UNKNOWN, user_psci_off);
>>> exit(report_summary());
>>> }
>> Thank you for posting this, when I started playing with kvm-unit-tests I noticed
>> that selftest-vectors-user isn't working, but I totally forgot about it. I am
>> interested in the patch, do you want to write the patch yourself? If not, I can
>> pick it up and submit it.
> I'll post it as 6/5 of this series. Have you reviewed/tested it? I.e. any
> tags you'd like me to add to the posting?
Commit 96d79976f7795 ("mark exit() and abort() as non-returning functions")
added __builtin_unreachable() after functions that are not expected to return.
You might want to add it after halt().
But other than that:
Reviewed-by: Alexandru Elisei <alexandru.elisei at arm.com>
Tested-by: Alexandru Elisei <alexandru.elisei at arm.com>
>
> Thanks,
> drew
>
>>>
>>> Anyway, thanks for submitting these patches to enable another user of
>>> kvm-unit-tests.
>>>
>>> drew
>>>
>>>
>>>> Changes in v3:
>>>> * Updated cover letter with information about the kvmtool --firmware
>>>> option.
>>>> * Gathered Reviewed-by tags.
>>>> * Renamed the config.h define UART_EARLY_BASE to CONFIG_UART_EARLY_BASE and
>>>> made the necessary casts in lib/arm/io.c
>>>>
>>>> Changes in v2:
>>>> * Generate lib/config.h when configuring kvm-unit-tests; arm/arm64 uses it
>>>> to get the UART address.
>>>> * Added --vmm configure option for arm/arm64 which will set the UART
>>>> address in lib/config.h when the tests are run under QEMU or kvmtool.
>>>> * Renamed psci_sys_reset() to psci_system_reset().
>>>> * Dropped patches that allowed a test to ignore unexpected command line
>>>> arguments.
>>>>
>>>> Summary:
>>>> * Patches 1, 2 and 3 add support for configuring kvm-unit-tests on arm and
>>>> arm64 to use the ns16550a UART emulated by kvmtool.
>>>> * Patches 4 and 5 provide an alternative mechanism for terminating the
>>>> virtual machine by using PSCI.
>>>>
>>>> [1] https://git.kernel.org/pub/scm/linux/kernel/git/will/kvmtool.git/
>>>> [2] https://www.spinics.net/lists/kvm-arm/msg34352.html
>>>>
>>>> Alexandru Elisei (5):
>>>> lib: arm: Use UART address from generated config.h
>>>> configure: arm/arm64: Add --vmm option with no effect
>>>> lib: arm: Use ns16550a UART when --vmm=kvmtool
>>>> lib: arm: Implement PSCI SYSTEM_OFF in psci_system_off()
>>>> lib: arm: Fallback to psci_system_off() in exit()
>>>>
>>>> configure | 32 ++++++++++++++++++++++++++++++++
>>>> Makefile | 2 +-
>>>> lib/arm/asm/psci.h | 3 ++-
>>>> lib/arm/io.c | 41 ++++++++++++++++++++++++++---------------
>>>> lib/arm/psci.c | 8 +++++++-
>>>> .gitignore | 1 +
>>>> 6 files changed, 69 insertions(+), 18 deletions(-)
>>>>
>>>> --
>>>> 2.17.0
>>>>
