* [PATCH 1/1 v2] [RISC-V/RVV] Expand the probe_pages helper function to handle probe flags.
2025-03-13 12:39 [PATCH 0/1 v2] [RISC-V/RVV] use a single function to probe memory Paolo Savini
@ 2025-03-13 12:39 ` Paolo Savini
2025-04-04 6:07 ` [PATCH 0/1 v2] [RISC-V/RVV] use a single function to probe memory Alistair Francis
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Savini @ 2025-03-13 12:39 UTC (permalink / raw)
To: qemu-devel, qemu-riscv
Cc: Paolo Savini, Richard Handerson, Palmer Dabbelt, Alistair Francis,
Bin Meng, Weiwei Li, Daniel Henrique Barboza, Liu Zhiwei,
Helene Chelin, Nathan Egge, Max Chou, Jeremy Bennett,
Craig Blackmore
This commit expands the probe_pages helper function in
target/riscv/vector_helper.c to handle also the cases in which we need access to
the flags raised while probing the memory and the host address.
This is done in order to provide a unified interface to probe_access and
probe_access_flags.
The new version of probe_pages can now act as a regular call to probe_access as
before and as a call to probe_access_flags. In the latter case the user need to
pass pointers to flags and host address and a boolean value for nonfault.
The flags and host address will be set and made available as for a direct call
to probe_access_flags.
Signed-off-by: Paolo Savini <paolo.savini@embecosm.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
target/riscv/vector_helper.c | 57 +++++++++++++++++++++++-------------
1 file changed, 37 insertions(+), 20 deletions(-)
diff --git a/target/riscv/vector_helper.c b/target/riscv/vector_helper.c
index 67b3bafebb..4bd511a03d 100644
--- a/target/riscv/vector_helper.c
+++ b/target/riscv/vector_helper.c
@@ -114,25 +114,42 @@ static inline uint32_t vext_max_elems(uint32_t desc, uint32_t log2_esz)
* It will trigger an exception if there is no mapping in TLB
* and page table walk can't fill the TLB entry. Then the guest
* software can return here after process the exception or never return.
+ *
+ * This function can also be used when direct access to probe_access_flags is
+ * needed in order to access the flags. If a pointer to a flags operand is
+ * provided the function will call probe_access_flags instead, use nonfault
+ * and update host and flags.
*/
-static void probe_pages(CPURISCVState *env, target_ulong addr,
- target_ulong len, uintptr_t ra,
- MMUAccessType access_type)
+static void probe_pages(CPURISCVState *env, target_ulong addr, target_ulong len,
+ uintptr_t ra, MMUAccessType access_type, int mmu_index,
+ void **host, int *flags, bool nonfault)
{
target_ulong pagelen = -(addr | TARGET_PAGE_MASK);
target_ulong curlen = MIN(pagelen, len);
- int mmu_index = riscv_env_mmu_index(env, false);
- probe_access(env, adjust_addr(env, addr), curlen, access_type,
- mmu_index, ra);
+ if (flags != NULL) {
+ *flags = probe_access_flags(env, adjust_addr(env, addr), curlen,
+ access_type, mmu_index, nonfault, host, ra);
+ } else {
+ probe_access(env, adjust_addr(env, addr), curlen, access_type,
+ mmu_index, ra);
+ }
+
if (len > curlen) {
addr += curlen;
curlen = len - curlen;
- probe_access(env, adjust_addr(env, addr), curlen, access_type,
- mmu_index, ra);
+ if (flags != NULL) {
+ *flags = probe_access_flags(env, adjust_addr(env, addr), curlen,
+ access_type, mmu_index, nonfault,
+ host, ra);
+ } else {
+ probe_access(env, adjust_addr(env, addr), curlen, access_type,
+ mmu_index, ra);
+ }
}
}
+
static inline void vext_set_elem_mask(void *v0, int index,
uint8_t value)
{
@@ -332,8 +349,8 @@ vext_page_ldst_us(CPURISCVState *env, void *vd, target_ulong addr,
MMUAccessType access_type = is_load ? MMU_DATA_LOAD : MMU_DATA_STORE;
/* Check page permission/pmp/watchpoint/etc. */
- flags = probe_access_flags(env, adjust_addr(env, addr), size, access_type,
- mmu_index, true, &host, ra);
+ probe_pages(env, addr, size, ra, access_type, mmu_index, &host, &flags,
+ true);
if (flags == 0) {
if (nf == 1) {
@@ -632,7 +649,7 @@ vext_ldff(void *vd, void *v0, target_ulong base, CPURISCVState *env,
uint32_t vma = vext_vma(desc);
target_ulong addr, addr_probe, addr_i, offset, remain, page_split, elems;
int mmu_index = riscv_env_mmu_index(env, false);
- int flags;
+ int flags, probe_flags;
void *host;
VSTART_CHECK_EARLY_EXIT(env, env->vl);
@@ -646,15 +663,15 @@ vext_ldff(void *vd, void *v0, target_ulong base, CPURISCVState *env,
}
/* Check page permission/pmp/watchpoint/etc. */
- flags = probe_access_flags(env, adjust_addr(env, addr), elems * msize,
- MMU_DATA_LOAD, mmu_index, true, &host, ra);
+ probe_pages(env, addr, elems * msize, ra, MMU_DATA_LOAD, mmu_index, &host,
+ &flags, true);
/* If we are crossing a page check also the second page. */
if (env->vl > elems) {
addr_probe = addr + (elems << log2_esz);
- flags |= probe_access_flags(env, adjust_addr(env, addr_probe),
- elems * msize, MMU_DATA_LOAD, mmu_index,
- true, &host, ra);
+ probe_pages(env, addr_probe, elems * msize, ra, MMU_DATA_LOAD,
+ mmu_index, &host, &probe_flags, true);
+ flags |= probe_flags;
}
if (flags & ~TLB_WATCHPOINT) {
@@ -666,16 +683,16 @@ vext_ldff(void *vd, void *v0, target_ulong base, CPURISCVState *env,
addr_i = adjust_addr(env, base + i * (nf << log2_esz));
if (i == 0) {
/* Allow fault on first element. */
- probe_pages(env, addr_i, nf << log2_esz, ra, MMU_DATA_LOAD);
+ probe_pages(env, addr_i, nf << log2_esz, ra, MMU_DATA_LOAD,
+ mmu_index, &host, NULL, false);
} else {
remain = nf << log2_esz;
while (remain > 0) {
offset = -(addr_i | TARGET_PAGE_MASK);
/* Probe nonfault on subsequent elements. */
- flags = probe_access_flags(env, addr_i, offset,
- MMU_DATA_LOAD, mmu_index, true,
- &host, 0);
+ probe_pages(env, addr_i, offset, 0, MMU_DATA_LOAD,
+ mmu_index, &host, &flags, true);
/*
* Stop if invalid (unmapped) or mmio (transaction may
--
2.34.1
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