qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Weiwei Li <liweiwei@iscas.ac.cn>
To: qemu-riscv@nongnu.org, qemu-devel@nongnu.org
Cc: palmer@dabbelt.com, alistair.francis@wdc.com,
	bin.meng@windriver.com, dbarboza@ventanamicro.com,
	zhiwei_liu@linux.alibaba.com, richard.henderson@linaro.org,
	wangjunqiang@iscas.ac.cn, lazyparser@gmail.com,
	Weiwei Li <liweiwei@iscas.ac.cn>
Subject: [PATCH v6 10/12] target/riscv: Flush TLB only when pmpcfg/pmpaddr really changes
Date: Wed, 17 May 2023 17:15:17 +0800	[thread overview]
Message-ID: <20230517091519.34439-11-liweiwei@iscas.ac.cn> (raw)
In-Reply-To: <20230517091519.34439-1-liweiwei@iscas.ac.cn>

TLB needn't be flushed when pmpcfg/pmpaddr don't changes.

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 target/riscv/pmp.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index 70fb2327f7..37b25e9b34 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -26,7 +26,7 @@
 #include "trace.h"
 #include "exec/exec-all.h"
 
-static void pmp_write_cfg(CPURISCVState *env, uint32_t addr_index,
+static bool pmp_write_cfg(CPURISCVState *env, uint32_t addr_index,
                           uint8_t val);
 static uint8_t pmp_read_cfg(CPURISCVState *env, uint32_t addr_index);
 static void pmp_update_rule(CPURISCVState *env, uint32_t pmp_index);
@@ -83,7 +83,7 @@ static inline uint8_t pmp_read_cfg(CPURISCVState *env, uint32_t pmp_index)
  * Accessor to set the cfg reg for a specific PMP/HART
  * Bounds checks and relevant lock bit.
  */
-static void pmp_write_cfg(CPURISCVState *env, uint32_t pmp_index, uint8_t val)
+static bool pmp_write_cfg(CPURISCVState *env, uint32_t pmp_index, uint8_t val)
 {
     if (pmp_index < MAX_RISCV_PMPS) {
         bool locked = true;
@@ -119,14 +119,17 @@ static void pmp_write_cfg(CPURISCVState *env, uint32_t pmp_index, uint8_t val)
 
         if (locked) {
             qemu_log_mask(LOG_GUEST_ERROR, "ignoring pmpcfg write - locked\n");
-        } else {
+        } else if (env->pmp_state.pmp[pmp_index].cfg_reg != val) {
             env->pmp_state.pmp[pmp_index].cfg_reg = val;
             pmp_update_rule(env, pmp_index);
+            return true;
         }
     } else {
         qemu_log_mask(LOG_GUEST_ERROR,
                       "ignoring pmpcfg write - out of bounds\n");
     }
+
+    return false;
 }
 
 static void pmp_decode_napot(target_ulong a, target_ulong *sa,
@@ -467,16 +470,19 @@ void pmpcfg_csr_write(CPURISCVState *env, uint32_t reg_index,
     int i;
     uint8_t cfg_val;
     int pmpcfg_nums = 2 << riscv_cpu_mxl(env);
+    bool modified = false;
 
     trace_pmpcfg_csr_write(env->mhartid, reg_index, val);
 
     for (i = 0; i < pmpcfg_nums; i++) {
         cfg_val = (val >> 8 * i)  & 0xff;
-        pmp_write_cfg(env, (reg_index * 4) + i, cfg_val);
+        modified |= pmp_write_cfg(env, (reg_index * 4) + i, cfg_val);
     }
 
     /* If PMP permission of any addr has been changed, flush TLB pages. */
-    tlb_flush(env_cpu(env));
+    if (modified) {
+        tlb_flush(env_cpu(env));
+    }
 }
 
 
@@ -526,12 +532,14 @@ void pmpaddr_csr_write(CPURISCVState *env, uint32_t addr_index,
         }
 
         if (!pmp_is_locked(env, addr_index)) {
-            env->pmp_state.pmp[addr_index].addr_reg = val;
-            pmp_update_rule_addr(env, addr_index);
-            if (is_next_cfg_tor) {
-                pmp_update_rule_addr(env, addr_index + 1);
+            if (env->pmp_state.pmp[addr_index].addr_reg != val) {
+                env->pmp_state.pmp[addr_index].addr_reg = val;
+                pmp_update_rule_addr(env, addr_index);
+                if (is_next_cfg_tor) {
+                    pmp_update_rule_addr(env, addr_index + 1);
+                }
+                tlb_flush(env_cpu(env));
             }
-            tlb_flush(env_cpu(env));
         } else {
             qemu_log_mask(LOG_GUEST_ERROR,
                           "ignoring pmpaddr write - locked\n");
-- 
2.25.1



  parent reply	other threads:[~2023-05-17  9:17 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-17  9:15 [PATCH v6 00/12] target/riscv: Fix PMP related problem Weiwei Li
2023-05-17  9:15 ` [PATCH v6 01/12] target/riscv: Update pmp_get_tlb_size() Weiwei Li
2023-05-17  9:15 ` [PATCH v6 02/12] target/riscv: Move pmp_get_tlb_size apart from get_physical_address_pmp Weiwei Li
2023-05-17  9:15 ` [PATCH v6 03/12] target/riscv: Make the short cut really work in pmp_hart_has_privs Weiwei Li
2023-05-17  9:15 ` [PATCH v6 04/12] target/riscv: Change the return type of pmp_hart_has_privs() to bool Weiwei Li
2023-05-17  9:15 ` [PATCH v6 05/12] target/riscv: Make RLB/MML/MMWP bits writable only when Smepmp is enabled Weiwei Li
2023-05-17  9:15 ` [PATCH v6 06/12] target/riscv: Remove unused paramters in pmp_hart_has_privs_default() Weiwei Li
2023-05-17  9:15 ` [PATCH v6 07/12] target/riscv: Flush TLB when MMWP or MML bits are changed Weiwei Li
2023-05-17  9:15 ` [PATCH v6 08/12] target/riscv: Update the next rule addr in pmpaddr_csr_write() Weiwei Li
2023-05-17  9:15 ` [PATCH v6 09/12] target/riscv: Flush TLB when pmpaddr is updated Weiwei Li
2023-05-17  9:15 ` Weiwei Li [this message]
2023-05-17  9:15 ` [PATCH v6 11/12] target/riscv: Separate pmp_update_rule() in pmpcfg_csr_write Weiwei Li
2023-05-17  9:15 ` [PATCH v6 12/12] target/riscv: Deny access if access is partially inside the PMP entry Weiwei Li
2023-05-18  9:46 ` [PATCH v6 00/12] target/riscv: Fix PMP related problem Alistair Francis

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230517091519.34439-11-liweiwei@iscas.ac.cn \
    --to=liweiwei@iscas.ac.cn \
    --cc=alistair.francis@wdc.com \
    --cc=bin.meng@windriver.com \
    --cc=dbarboza@ventanamicro.com \
    --cc=lazyparser@gmail.com \
    --cc=palmer@dabbelt.com \
    --cc=qemu-devel@nongnu.org \
    --cc=qemu-riscv@nongnu.org \
    --cc=richard.henderson@linaro.org \
    --cc=wangjunqiang@iscas.ac.cn \
    --cc=zhiwei_liu@linux.alibaba.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).