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[Qemu-devel] [PULL 45/45] target/arm: Only flush tlb if ASID changes
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PULL 45/45] target/arm: Only flush tlb if ASID changes |
Date: |
Fri, 19 Oct 2018 17:57:35 +0100 |
From: Richard Henderson <address@hidden>
Since QEMU does not implement ASIDs, changes to the ASID must flush the
tlb. However, if the ASID does not change there is no reason to flush.
In testing a boot of the Ubuntu installer to the first menu, this reduces
the number of flushes by 30%, or nearly 600k instances.
Reviewed-by: Aaron Lindsay <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
Reviewed-by: Peter Maydell <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Message-id: address@hidden
Signed-off-by: Peter Maydell <address@hidden>
---
target/arm/helper.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 20114bf574d..bea4d5350d1 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -2758,12 +2758,10 @@ static void vmsa_tcr_el1_write(CPUARMState *env, const
ARMCPRegInfo *ri,
static void vmsa_ttbr_write(CPUARMState *env, const ARMCPRegInfo *ri,
uint64_t value)
{
- /* 64 bit accesses to the TTBRs can change the ASID and so we
- * must flush the TLB.
- */
- if (cpreg_field_is_64bit(ri)) {
+ /* If the ASID changes (with a 64-bit write), we must flush the TLB. */
+ if (cpreg_field_is_64bit(ri) &&
+ extract64(raw_read(env, ri) ^ value, 48, 16) != 0) {
ARMCPU *cpu = arm_env_get_cpu(env);
-
tlb_flush(CPU(cpu));
}
raw_write(env, ri, value);
--
2.19.1
- [Qemu-devel] [PULL 03/45] target/arm: Move some system registers into a substructure, (continued)
- [Qemu-devel] [PULL 03/45] target/arm: Move some system registers into a substructure, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 05/45] target/arm: Convert v8 extensions from feature bits to isar tests, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 10/45] target/arm: Convert v8.2-fp16 from feature bit to aa64pfr0 test, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 11/45] target/arm: Improve debug logging of AArch32 exception return, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 21/45] hw/arm/boot: Increase compliance with kernel arm64 boot protocol, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 20/45] target/arm: Report correct syndrome for FP/SIMD traps to Hyp mode, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 22/45] target/arm: Hoist address increment for vector memory ops, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 36/45] target/arm: Use gvec for NEON_3R_VML, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 35/45] target/arm: Use gvec for VSRI, VSLI, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 38/45] target/arm: Use gvec for NEON VLD all lanes, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 45/45] target/arm: Only flush tlb if ASID changes,
Peter Maydell <=
- [Qemu-devel] [PULL 44/45] target/arm: Remove writefn from TTBR0_EL3, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 43/45] net: cadence_gem: Announce 64bit addressing support, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 42/45] net: cadence_gem: Announce availability of priority queues, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 41/45] target/arm: Reorg NEON VLD/VST single element to one lane, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 40/45] target/arm: Promote consecutive memory ops for aa32, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 39/45] target/arm: Reorg NEON VLD/VST all elements, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 37/45] target/arm: Use gvec for NEON_3R_VTST_VCEQ, NEON_3R_VCGT, NEON_3R_VCGE, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 34/45] target/arm: Use gvec for VSRA, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 33/45] target/arm: Use gvec for VSHR, VSHL, Peter Maydell, 2018/10/19
- [Qemu-devel] [PULL 32/45] target/arm: Use gvec for NEON_3R_VMUL, Peter Maydell, 2018/10/19