[PATCH] lib: sbi: Preserve hcounteren and htimedelta across domain switches

[Anup Patel]

On Fri, Oct 23, 2026 at 5:32 AM whensun
<theodoruswensanfebruanto025 at gmail.com> wrote:
>
> Save and restore hcounteren and htimedelta when switching between
> domains on harts supporting the Hypervisor extension.
>
> Without this preservation, a resumed domain can observe the register
> values left by another domain.
>
> Link: https://github.com/riscv-software-src/opensbi/issues/433
> Signed-off-by: whensun <theodoruswensanfebruanto025 at gmail.com>

Squash this in appropriate patch of your other series "Preserve more
S/HS architectural state across domain switches"

Regards,
Anup

> ---
>  lib/sbi/sbi_domain_context.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/lib/sbi/sbi_domain_context.c b/lib/sbi/sbi_domain_context.c
> index 0861d541..31fa5afc 100644
> --- a/lib/sbi/sbi_domain_context.c
> +++ b/lib/sbi/sbi_domain_context.c
> @@ -50,6 +50,8 @@ struct hart_context {
>         unsigned long senvcfg;
>         /** Supervisor resource management configuration register */
>         unsigned long srmcfg;
> +       unsigned long hcounteren;
> +       u64 htimedelta;
>
>         /** Float context state */
>         struct sbi_fp_context fp_ctx;
> @@ -145,6 +147,10 @@ static int switch_to_next_domain_context(struct hart_context *ctx,
>                 ctx->senvcfg    = csr_swap(CSR_SENVCFG, dom_ctx->senvcfg);
>         if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSQOSID))
>                 ctx->srmcfg     = csr_swap(CSR_SRMCFG, dom_ctx->srmcfg);
> +       if (misa_extension('H')) {
> +               ctx->hcounteren = csr_swap(CSR_HCOUNTEREN, dom_ctx->hcounteren);
> +               ctx->htimedelta = csr_swap64(CSR_HTIMEDELTA, dom_ctx->htimedelta);
> +       }
>
>         /* Eager context switch for float */
>         if (sbi_hart_has_extension(scratch, SBI_HART_EXT_F) ||
> --
> 2.43.0
>
>
> --
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