[kvm-unit-tests PATCH 11/10] riscv: sbi: Add fwft pte_hw_ad_updating test
Andrew Jones
andrew.jones at linux.dev
Wed Feb 26 09:59:12 PST 2025
Add SBI FWFT tests for the PTE_HW_AD_UPDATING feature.
Signed-off-by: Andrew Jones <andrew.jones at linux.dev>
---
lib/riscv/asm/mmu.h | 3 +
lib/riscv/mmu.c | 7 ++
riscv/sbi-fwft.c | 162 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 172 insertions(+)
diff --git a/lib/riscv/asm/mmu.h b/lib/riscv/asm/mmu.h
index 28c332f11496..4cdc1f77d884 100644
--- a/lib/riscv/asm/mmu.h
+++ b/lib/riscv/asm/mmu.h
@@ -32,4 +32,7 @@ static inline void local_flush_tlb_page(unsigned long addr)
*/
pte_t *get_pte(pgd_t *pgtable, uintptr_t vaddr);
+/* Update the pgprot to @prot for the pte of the corresponding @addr */
+void pte_update_prot(unsigned long addr, pteval_t prot);
+
#endif /* _ASMRISCV_MMU_H_ */
diff --git a/lib/riscv/mmu.c b/lib/riscv/mmu.c
index 577c66aa77ba..4438327f6ffe 100644
--- a/lib/riscv/mmu.c
+++ b/lib/riscv/mmu.c
@@ -54,6 +54,13 @@ pte_t *get_pte(pgd_t *pgtable, uintptr_t vaddr)
return ptep;
}
+void pte_update_prot(unsigned long addr, pteval_t prot)
+{
+ pte_t *ptep = get_pte(current_pgtable(), addr);
+ *ptep = __pte(pte_val(*ptep) | prot);
+ local_flush_tlb_page(addr);
+}
+
static pteval_t *__install_page(pgd_t *pgtable, phys_addr_t paddr,
uintptr_t vaddr, pgprot_t prot, bool flush)
{
diff --git a/riscv/sbi-fwft.c b/riscv/sbi-fwft.c
index 0a70192b1da5..2b65285c82fc 100644
--- a/riscv/sbi-fwft.c
+++ b/riscv/sbi-fwft.c
@@ -5,9 +5,12 @@
* Copyright (C) 2024, Rivos Inc., Clément Léger <cleger at rivosinc.com>
*/
#include <libcflat.h>
+#include <alloc.h>
#include <stdlib.h>
#include <asm/csr.h>
+#include <asm/io.h>
+#include <asm/mmu.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/sbi.h>
@@ -160,6 +163,164 @@ static void fwft_check_misaligned_exc_deleg(void)
report_prefix_pop();
}
+static bool adue_triggered_read, adue_triggered_write;
+
+static void adue_read_handler(struct pt_regs *regs)
+{
+ adue_triggered_read = true;
+ pte_update_prot(regs->badaddr, _PAGE_ACCESSED);
+}
+
+static void adue_write_handler(struct pt_regs *regs)
+{
+ adue_triggered_write = true;
+ pte_update_prot(regs->badaddr, _PAGE_ACCESSED | _PAGE_DIRTY);
+}
+
+static bool adue_check_pte(pteval_t pte, bool write)
+{
+ return (pte & (_PAGE_ACCESSED | _PAGE_DIRTY)) == (_PAGE_ACCESSED | (write ? _PAGE_DIRTY : 0));
+}
+
+static void __adue_check(bool hw_updating_enabled, bool write)
+{
+ unsigned long *ptr = malloc(sizeof(unsigned long));
+ pte_t *ptep = get_pte(current_pgtable(), (uintptr_t)ptr);
+ bool *triggered;
+ const char *op;
+
+ WRITE_ONCE(adue_triggered_read, false);
+ WRITE_ONCE(adue_triggered_write, false);
+
+ *ptep = __pte(pte_val(*ptep) & ~(_PAGE_ACCESSED | _PAGE_DIRTY));
+ local_flush_tlb_page((uintptr_t)ptr);
+
+ if (write) {
+ op = "write";
+ triggered = &adue_triggered_write;
+ writel(0xdeadbeef, ptr);
+ } else {
+ op = "read";
+ triggered = &adue_triggered_read;
+ readl(ptr);
+ }
+
+ ptep = get_pte(current_pgtable(), (uintptr_t)ptr);
+
+ report(hw_updating_enabled != *triggered &&
+ adue_check_pte(pte_val(*ptep), write), "%s %s",
+ hw_updating_enabled ? "hw updating enabled" : "hw updating disabled", op);
+
+ free(ptr);
+}
+
+static void adue_check(bool hw_updating_enabled)
+{
+ __adue_check(hw_updating_enabled, false);
+ __adue_check(hw_updating_enabled, true);
+}
+
+static void fwft_check_pte_ad_hw_updating(void)
+{
+ struct sbiret ret;
+ bool enabled;
+
+ report_prefix_push("pte_ad_hw_updating");
+
+ ret = fwft_get(SBI_FWFT_PTE_AD_HW_UPDATING);
+ if (ret.error == SBI_ERR_NOT_SUPPORTED) {
+ report_skip("not supported by platform");
+ return;
+ } else if (!sbiret_report_error(&ret, SBI_SUCCESS, "get")) {
+ /* Not much we can do without a working get... */
+ return;
+ }
+
+ enabled = !!ret.value;
+ report(!enabled, "resets to 0");
+
+ install_exception_handler(EXC_LOAD_PAGE_FAULT, adue_read_handler);
+ install_exception_handler(EXC_STORE_PAGE_FAULT, adue_write_handler);
+
+ adue_check(enabled);
+
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, !enabled, 0);
+ if (!sbiret_report_error(&ret, SBI_SUCCESS, "set to %d", !enabled))
+ goto inval_tests;
+ else
+ enabled = !enabled;
+
+ ret = fwft_get(SBI_FWFT_PTE_AD_HW_UPDATING);
+ sbiret_report(&ret, SBI_SUCCESS, enabled, "get %d", enabled);
+
+ adue_check(enabled);
+
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, !enabled, 0);
+ if (!sbiret_report_error(&ret, SBI_SUCCESS, "set to %d again", !enabled))
+ goto inval_tests;
+ else
+ enabled = !enabled;
+
+ ret = fwft_get(SBI_FWFT_PTE_AD_HW_UPDATING);
+ sbiret_report(&ret, SBI_SUCCESS, enabled, "get %d again", enabled);
+
+ adue_check(enabled);
+
+#if __riscv_xlen > 32
+ ret = fwft_set_raw(BIT(32) | SBI_FWFT_PTE_AD_HW_UPDATING, !enabled, 0);
+ if (!sbiret_report_error(&ret, SBI_SUCCESS, "set to %d with high feature bits set", !enabled))
+ goto inval_tests;
+ else
+ enabled = !enabled;
+
+ ret = fwft_get(SBI_FWFT_PTE_AD_HW_UPDATING);
+ sbiret_report(&ret, SBI_SUCCESS, enabled, "get %d after set with high feature bits set", enabled);
+
+ adue_check(enabled);
+#endif
+
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, !enabled, 1);
+ if (!sbiret_report_error(&ret, SBI_SUCCESS, "set to %d with lock", !enabled))
+ goto inval_tests;
+ else
+ enabled = !enabled;
+
+ ret = fwft_get(SBI_FWFT_PTE_AD_HW_UPDATING);
+ sbiret_report(&ret, SBI_SUCCESS, enabled, "get %d after set with lock", enabled);
+
+ adue_check(enabled);
+
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, !enabled, 0);
+ sbiret_report_error(&ret, SBI_ERR_DENIED_LOCKED, "set locked to %d without lock", !enabled);
+
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, !enabled, 1);
+ sbiret_report_error(&ret, SBI_ERR_DENIED_LOCKED, "set locked to %d with lock", !enabled);
+
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, enabled, 0);
+ sbiret_report_error(&ret, SBI_ERR_DENIED_LOCKED, "set locked to %d without lock", enabled);
+
+ ret = fwft_get(SBI_FWFT_PTE_AD_HW_UPDATING);
+ sbiret_report(&ret, SBI_SUCCESS, enabled, "get locked %d after same set without lock", enabled);
+
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, enabled, 1);
+ sbiret_report_error(&ret, SBI_ERR_DENIED_LOCKED, "set locked to %d with lock", enabled);
+
+ ret = fwft_get(SBI_FWFT_PTE_AD_HW_UPDATING);
+ sbiret_report(&ret, SBI_SUCCESS, enabled, "get locked %d after same set with lock", enabled);
+
+inval_tests:
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, 2, 0);
+ sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM, "set to 2");
+
+ ret = fwft_set(SBI_FWFT_PTE_AD_HW_UPDATING, !enabled, 2);
+ sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM, "set to %d with flags=2", !enabled);
+
+ install_exception_handler(EXC_LOAD_PAGE_FAULT, NULL);
+ install_exception_handler(EXC_STORE_PAGE_FAULT, NULL);
+
+ report_prefix_pop();
+}
+
void check_fwft(void)
{
report_prefix_push("fwft");
@@ -174,6 +335,7 @@ void check_fwft(void)
fwft_check_base();
fwft_check_misaligned_exc_deleg();
+ fwft_check_pte_ad_hw_updating();
report_prefix_pop();
}
--
2.48.1
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