Re: [Qemu-riscv] [Qemu-devel] [PATCH] target/riscv: Do not allow sfence.vma from user mode

[Alistair Francis]

On Fri, Apr 12, 2019 at 2:15 PM Jonathan Behrens <address@hidden> wrote:
>
> Just to double check, nothing further on this is need from me, right? It is 
> set to be merged onto the master branch once the 4.0 release is out?

Thanks for checking!

Yep you don't need to do anything, Palmer will merge it in the next
RISC-V PR after 4.0.

Alistair

>
> Jonathan
>
> On Wed, Apr 3, 2019 at 7:11 PM Alistair Francis <address@hidden> wrote:
>>
>> On Mon, Apr 1, 2019 at 1:39 PM Jonathan Behrens <address@hidden> wrote:
>> >
>> > The 'sfence.vma' instruction is privileged, and should only ever be allowed
>> > when executing in supervisor mode or higher.
>> >
>> > Jonathan
>> >
>> > Signed-off-by: Jonathan Behrens <address@hidden>
>>
>> Reviewed-by: Alistair Francis <address@hidden>
>>
>> Alistair
>>
>> > ---
>> >  target/riscv/op_helper.c | 7 ++++---
>> >  1 file changed, 4 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
>> > index b7dc18a41e..644d0fb35f 100644
>> > --- a/target/riscv/op_helper.c
>> > +++ b/target/riscv/op_helper.c
>> > @@ -145,9 +145,10 @@ void helper_tlb_flush(CPURISCVState *env)
>> >  {
>> >      RISCVCPU *cpu = riscv_env_get_cpu(env);
>> >      CPUState *cs = CPU(cpu);
>> > -    if (env->priv == PRV_S &&
>> > -        env->priv_ver >= PRIV_VERSION_1_10_0 &&
>> > -        get_field(env->mstatus, MSTATUS_TVM)) {
>> > +    if (!(env->priv >= PRV_S) ||
>> > +        (env->priv == PRV_S &&
>> > +         env->priv_ver >= PRIV_VERSION_1_10_0 &&
>> > +         get_field(env->mstatus, MSTATUS_TVM))) {
>> >          riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
>> >      } else {
>> >          tlb_flush(cs);
>> > --
>> > 2.20.1