| Message ID | c5e918630ba37273d7b0f4e4dbb6f90d4c2f321d.1668347565.git.christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | RISC-V: KVM: Simplify kvm_arch_prepare_memory_region() | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/patch_count | success | Link |
| conchuod/cover_letter | success | Single patches do not need cover letters |
| conchuod/tree_selection | success | Guessed tree name to be for-next |
| conchuod/fixes_present | success | Fixes tag not required for -next series |
| conchuod/verify_signedoff | success | Signed-off-by tag matches author and committer |
| conchuod/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/module_param | success | Was 0 now: 0 |
| conchuod/build_rv32_defconfig | success | Build OK |
| conchuod/build_warn_rv64 | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/dtb_warn_rv64 | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/header_inline | success | No static functions without inline keyword in header files |
| conchuod/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 11 lines checked |
| conchuod/source_inline | success | Was 0 now: 0 |
| conchuod/build_rv64_nommu_k210_defconfig | success | Build OK |
| conchuod/verify_fixes | success | No Fixes tag |
| conchuod/build_rv64_nommu_virt_defconfig | success | Build OK |
On Sun, Nov 13, 2022 at 7:22 PM Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote: > > In kvm_arch_prepare_memory_region(), if no error occurs, a spin_lock()/ > spin_unlock() call can be avoided. > > Switch to kvm_riscv_gstage_iounmap() that is the same as the current code, > but with a better semantic. > It also embeds the locking logic. So it is avoided if ret == 0. > > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Looks good to me. Reviewed-by: Anup Patel <anup@brainfault.org> I have tested this on QEMU virt machine for RV64. Queued this patch for Linux-6.2 Thanks, Anup > --- > I don't use cross-compiler, so this patch is NOT even compile tested. > --- > arch/riscv/kvm/mmu.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c > index 3620ecac2fa1..c8834e463763 100644 > --- a/arch/riscv/kvm/mmu.c > +++ b/arch/riscv/kvm/mmu.c > @@ -537,10 +537,8 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, > if (change == KVM_MR_FLAGS_ONLY) > goto out; > > - spin_lock(&kvm->mmu_lock); > if (ret) > - gstage_unmap_range(kvm, base_gpa, size, false); > - spin_unlock(&kvm->mmu_lock); > + kvm_riscv_gstage_iounmap(kvm, base_gpa, size); > > out: > mmap_read_unlock(current->mm); > -- > 2.34.1 >
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 3620ecac2fa1..c8834e463763 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -537,10 +537,8 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if (change == KVM_MR_FLAGS_ONLY) goto out; - spin_lock(&kvm->mmu_lock); if (ret) - gstage_unmap_range(kvm, base_gpa, size, false); - spin_unlock(&kvm->mmu_lock); + kvm_riscv_gstage_iounmap(kvm, base_gpa, size); out: mmap_read_unlock(current->mm);
In kvm_arch_prepare_memory_region(), if no error occurs, a spin_lock()/ spin_unlock() call can be avoided. Switch to kvm_riscv_gstage_iounmap() that is the same as the current code, but with a better semantic. It also embeds the locking logic. So it is avoided if ret == 0. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- I don't use cross-compiler, so this patch is NOT even compile tested. --- arch/riscv/kvm/mmu.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)