[v2] Add RISC-V Hypervisor Extension v0.5

[PATCH v2 26/35] target/riscv: Disable guest FP support based on virtual status

Posted by Alistair Francis 6 years ago

When the Hypervisor extension is in use we only enable floating point
support when both status and vsstatus have enabled floating point
support.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu_helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index e7728cb0ca..827a38324c 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -99,6 +99,9 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
 bool riscv_cpu_fp_enabled(CPURISCVState *env)
 {
     if (env->mstatus & MSTATUS_FS) {
+        if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
+            return false;
+        }
         return true;
     }
 
-- 
2.25.0

Re: [PATCH v2 26/35] target/riscv: Disable guest FP support based on virtual status

Posted by Palmer Dabbelt 5 years, 12 months ago

On Fri, 31 Jan 2020 17:02:44 PST (-0800), Alistair Francis wrote:
> When the Hypervisor extension is in use we only enable floating point
> support when both status and vsstatus have enabled floating point
> support.
>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu_helper.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index e7728cb0ca..827a38324c 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -99,6 +99,9 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
>  bool riscv_cpu_fp_enabled(CPURISCVState *env)
>  {
>      if (env->mstatus & MSTATUS_FS) {
> +        if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
> +            return false;
> +        }
>          return true;
>      }

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>