| Message ID | c5e918630ba37273d7b0f4e4dbb6f90d4c2f321d.1668347565.git.christophe.jaillet@wanadoo.fr |
|---|---|
| State | Accepted |
| Headers | show |
| Series | RISC-V: KVM: Simplify kvm_arch_prepare_memory_region() | expand |
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(-)