target: riscv: Add Svvptc extension support

The Svvptc extension describes a uarch that does not cache invalid TLB
entries: that's the case for qemu so there is nothing particular to
implement other than the introduction of this extension.

Since qemu already exposes Svvptc behaviour, let's enable it by default
since it allows to drastically reduce the number of sfence.vma emitted
by S-mode.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240828083651.203861-1-alexghiti@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 89bc3955eeef23cf0286f293d409043edab8c66e..658bdb4ae19aa28bae06db2b07db3c4352b62563 100644 (file)
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -197,6 +197,7 @@ const RISCVIsaExtData isa_edata_arr[] = {
     ISA_EXT_DATA_ENTRY(svinval, PRIV_VERSION_1_12_0, ext_svinval),
     ISA_EXT_DATA_ENTRY(svnapot, PRIV_VERSION_1_12_0, ext_svnapot),
     ISA_EXT_DATA_ENTRY(svpbmt, PRIV_VERSION_1_12_0, ext_svpbmt),
+    ISA_EXT_DATA_ENTRY(svvptc, PRIV_VERSION_1_13_0, ext_svvptc),
     ISA_EXT_DATA_ENTRY(xtheadba, PRIV_VERSION_1_11_0, ext_xtheadba),
     ISA_EXT_DATA_ENTRY(xtheadbb, PRIV_VERSION_1_11_0, ext_xtheadbb),
     ISA_EXT_DATA_ENTRY(xtheadbs, PRIV_VERSION_1_11_0, ext_xtheadbs),
@@ -1494,6 +1495,7 @@ const RISCVCPUMultiExtConfig riscv_cpu_extensions[] = {
     MULTI_EXT_CFG_BOOL("svinval", ext_svinval, false),
     MULTI_EXT_CFG_BOOL("svnapot", ext_svnapot, false),
     MULTI_EXT_CFG_BOOL("svpbmt", ext_svpbmt, false),
+    MULTI_EXT_CFG_BOOL("svvptc", ext_svvptc, true),
 
     MULTI_EXT_CFG_BOOL("zicntr", ext_zicntr, true),
     MULTI_EXT_CFG_BOOL("zihpm", ext_zihpm, true),

diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h
index 96fe26d4eac499f5791ae14e189d75c70a005021..355afedfd30c5682e7bac4db83c67155994e59b4 100644 (file)
--- a/target/riscv/cpu_cfg.h
+++ b/target/riscv/cpu_cfg.h
@@ -81,6 +81,7 @@ struct RISCVCPUConfig {
     bool ext_svinval;
     bool ext_svnapot;
     bool ext_svpbmt;
+    bool ext_svvptc;
     bool ext_zdinx;
     bool ext_zaamo;
     bool ext_zacas;