Messages in this thread Patch in this message | | | From | Anup Patel <> | Date | Sun, 26 Jul 2020 18:27:16 +0530 | Subject | Re: [RFC 2/2] RISC-V: KVM: read\write kernel mmio device support |
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On Fri, Jul 24, 2020 at 2:25 PM Yifei Jiang <jiangyifei@huawei.com> wrote: > > Signed-off-by: Yifei Jiang <jiangyifei@huawei.com> > Signed-off-by: Mingwang Li <limingwang@huawei.com> > --- > arch/riscv/kvm/vcpu_exit.c | 38 ++++++++++++++++++++++++++++++++------ > 1 file changed, 32 insertions(+), 6 deletions(-) > > diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c > index e97ba96cb0ae..448f11179fa8 100644 > --- a/arch/riscv/kvm/vcpu_exit.c > +++ b/arch/riscv/kvm/vcpu_exit.c > @@ -191,6 +191,8 @@ static int virtual_inst_fault(struct kvm_vcpu *vcpu, struct kvm_run *run, > static int emulate_load(struct kvm_vcpu *vcpu, struct kvm_run *run, > unsigned long fault_addr, unsigned long htinst) > { > + int ret; > + u8 data_buf[8]; > unsigned long insn; > int shift = 0, len = 0; > struct kvm_cpu_trap utrap = { 0 }; > @@ -272,19 +274,32 @@ static int emulate_load(struct kvm_vcpu *vcpu, struct kvm_run *run, > vcpu->arch.mmio_decode.len = len; > vcpu->arch.mmio_decode.return_handled = 0; > > - /* Exit to userspace for MMIO emulation */ > - vcpu->stat.mmio_exit_user++; > - run->exit_reason = KVM_EXIT_MMIO; > + ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, fault_addr, len, > + data_buf); > +
Move "ret = kvm_io_bus_read()" just before "if (!ret)".
> run->mmio.is_write = false; > run->mmio.phys_addr = fault_addr; > run->mmio.len = len; > > + if (!ret) { > + /* We handled the access successfully in the kernel. */ > + memcpy(run->mmio.data, data_buf, len); > + vcpu->stat.mmio_exit_kernel++; > + kvm_riscv_vcpu_mmio_return(vcpu, run); > + return 1; > + } > + > + /* Exit to userspace for MMIO emulation */ > + vcpu->stat.mmio_exit_user++; > + run->exit_reason = KVM_EXIT_MMIO; > + > return 0; > } > > static int emulate_store(struct kvm_vcpu *vcpu, struct kvm_run *run, > unsigned long fault_addr, unsigned long htinst) > { > + int ret; > u8 data8; > u16 data16; > u32 data32; > @@ -378,13 +393,24 @@ static int emulate_store(struct kvm_vcpu *vcpu, struct kvm_run *run, > return -ENOTSUPP; > }; > > - /* Exit to userspace for MMIO emulation */ > - vcpu->stat.mmio_exit_user++; > - run->exit_reason = KVM_EXIT_MMIO; > + ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, fault_addr, len, > + run->mmio.data); > +
Same as above.
Move "ret = kvm_io_bus_write()" just before "if (!ret) {"
> run->mmio.is_write = true; > run->mmio.phys_addr = fault_addr; > run->mmio.len = len; > > + if (!ret) { > + /* We handled the access successfully in the kernel. */ > + vcpu->stat.mmio_exit_kernel++; > + kvm_riscv_vcpu_mmio_return(vcpu, run); > + return 1; > + } > + > + /* Exit to userspace for MMIO emulation */ > + vcpu->stat.mmio_exit_user++; > + run->exit_reason = KVM_EXIT_MMIO; > + > return 0; > } > > -- > 2.19.1 > >
Regards, Anup
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