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

[whensun]

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>
---
 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