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| author | Daniel Henrique Barboza <dbarboza@ventanamicro.com> | 2023-08-03 13:33:00 -0300 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2023-08-08 17:25:58 +0530 |
| commit | 1099c80906d358db542c64aba370291ae4b932b7 (patch) | |
| tree | fe6a1519846b8bfeb703a9247601ac07e342193d | |
| parent | RISC-V: KVM: avoid EBUSY when writing the same machine ID val (diff) | |
| download | linux-1099c80906d358db542c64aba370291ae4b932b7.tar.gz linux-1099c80906d358db542c64aba370291ae4b932b7.zip | |
RISC-V: KVM: avoid EBUSY when writing the same isa_ext val
riscv_vcpu_set_isa_ext_single() will prevent any write of isa_ext regs
if the vcpu already started spinning.
But if there's no extension state (enabled/disabled) made by the
userspace, there's no need to -EBUSY out - we can treat the operation as
a no-op.
zicbom/zicboz_block_size, ISA config reg and mvendorid/march/mimpid
already works in a more permissive manner w.r.t userspace writes being a
no-op, so let's do the same with isa_ext writes.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
| -rw-r--r-- | arch/riscv/kvm/vcpu_onereg.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c index 81cb6b2784db..989ea32dbcbe 100644 --- a/arch/riscv/kvm/vcpu_onereg.c +++ b/arch/riscv/kvm/vcpu_onereg.c @@ -482,6 +482,9 @@ static int riscv_vcpu_set_isa_ext_single(struct kvm_vcpu *vcpu, if (!__riscv_isa_extension_available(NULL, host_isa_ext)) return -ENOENT; + if (reg_val == test_bit(host_isa_ext, vcpu->arch.isa)) + return 0; + if (!vcpu->arch.ran_atleast_once) { /* * All multi-letter extension and a few single letter |