Re: [PATCH v1 3/4] selftests: kvm: Add ucall tests for LoongArch KVM

[zhaotianrui]

在 2023/8/3 上午2:08, Sean Christopherson 写道:
> On Tue, Aug 01, 2023, Tianrui Zhao wrote:
> > Add ucall tests for LoongArch KVM, it means that VM use hypercall
> s/tests/support
Thanks, I will fix this comment.
> > to return to userspace and handle the mmio exception.
> >
> > Based-on: <20230720062813.4126751-1-zhaotianrui@xxxxxxxxxxx>
> > Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
> > ---
> >   .../selftests/kvm/lib/loongarch/ucall.c       | 44 +++++++++++++++++++
> >   1 file changed, 44 insertions(+)
> >   create mode 100644 tools/testing/selftests/kvm/lib/loongarch/ucall.c
> >
> > diff --git a/tools/testing/selftests/kvm/lib/loongarch/ucall.c b/tools/testing/selftests/kvm/lib/loongarch/ucall.c
> > new file mode 100644
> > index 000000000000..b32f7c7f6548
> > --- /dev/null
> > +++ b/tools/testing/selftests/kvm/lib/loongarch/ucall.c
> > @@ -0,0 +1,44 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * ucall support. A ucall is a "hypercall to userspace".
> > + *
> > + */
> > +#include "kvm_util.h"
> > +
> > +/*
> > + * ucall_exit_mmio_addr holds per-VM values (global data is duplicated by each
> > + * VM), it must not be accessed from host code.
> > + */
> > +static vm_vaddr_t *ucall_exit_mmio_addr;
> > +
> > +void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
> > +{
> > +	vm_vaddr_t mmio_gva = vm_vaddr_unused_gap(vm, vm->page_size, KVM_UTIL_MIN_VADDR);
> > +
> > +	virt_map(vm, mmio_gva, mmio_gpa, 1);
> > +
> > +	vm->ucall_mmio_addr = mmio_gpa;
> > +
> > +	write_guest_global(vm, ucall_exit_mmio_addr, (vm_vaddr_t *)mmio_gva);
> > +}
> > +
> > +void ucall_arch_do_ucall(vm_vaddr_t uc)
> > +{
> > +
> Extra newline.
Thanks, I will remove this line.

Thanks
Tianrui Zhao
> > +	WRITE_ONCE(*ucall_exit_mmio_addr, uc);
> > +}
> > +
> > +void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
> > +{
> > +	struct kvm_run *run = vcpu->run;
> > +
> > +	if (run->exit_reason == KVM_EXIT_MMIO &&
> > +	    run->mmio.phys_addr == vcpu->vm->ucall_mmio_addr) {
> > +		TEST_ASSERT(run->mmio.is_write && run->mmio.len == sizeof(uint64_t),
> > +			    "Unexpected ucall exit mmio address access");
> > +
> > +		return (void *)(*((uint64_t *)run->mmio.data));
> > +	}
> > +
> > +	return NULL;
> > +}
> > --
> > 2.39.1