Commit 980f9ce4 authored by Andrew Jones's avatar Andrew Jones Committed by Wentao Guan
Browse files

riscv: KVM: Fix SBI IPI error generation 

stable inclusion
from stable-v6.6.81
commit f9dd51830d3076948540fb3f953f350927a7705b
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBYZED

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f9dd51830d3076948540fb3f953f350927a7705b



--------------------------------

[ Upstream commit 0611f78f83c93c000029ab01daa28166d03590ed ]

When an invalid function ID of an SBI extension is used we should
return not-supported, not invalid-param. Also, when we see that at
least one hartid constructed from the base and mask parameters is
invalid, then we should return invalid-param. Finally, rather than
relying on overflowing a left shift to result in zero and then using
that zero in a condition which [correctly] skips sending an IPI (but
loops unnecessarily), explicitly check for overflow and exit the loop
immediately.

Fixes: 5f862df5 ("RISC-V: KVM: Add v0.1 replacement SBI extensions defined in v0.2")
Signed-off-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Reviewed-by: default avatarAnup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20250217084506.18763-10-ajones@ventanamicro.com


Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
(cherry picked from commit f9dd51830d3076948540fb3f953f350927a7705b)
Signed-off-by: default avatarWentao Guan <guanwentao@uniontech.com>
parent 7159902c

arch/riscv/kvm/vcpu_sbi_replace.c

+11 −2
Original line number Diff line number Diff line
@@ -51,9 +51,10 @@ static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, 
	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;

	unsigned long hmask = cp->a0;

	unsigned long hbase = cp->a1;

	unsigned long hart_bit = 0, sentmask = 0;



	if (cp->a6 != SBI_EXT_IPI_SEND_IPI) {

		retdata->err_val = SBI_ERR_INVALID_PARAM;

		retdata->err_val = SBI_ERR_NOT_SUPPORTED;

		return 0;

	}
@@ -62,15 +63,23 @@ static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, 
		if (hbase != -1UL) {

			if (tmp->vcpu_id < hbase)

				continue;

			if (!(hmask & (1UL << (tmp->vcpu_id - hbase))))

			hart_bit = tmp->vcpu_id - hbase;

			if (hart_bit >= __riscv_xlen)

				goto done;

			if (!(hmask & (1UL << hart_bit)))

				continue;

		}

		ret = kvm_riscv_vcpu_set_interrupt(tmp, IRQ_VS_SOFT);

		if (ret < 0)

			break;

		sentmask |= 1UL << hart_bit;

		kvm_riscv_vcpu_pmu_incr_fw(tmp, SBI_PMU_FW_IPI_RCVD);

	}



done:

	if (hbase != -1UL && (hmask ^ sentmask))

		retdata->err_val = SBI_ERR_INVALID_PARAM;



	return ret;

}