6.17-stable review patch. If anyone has any objections, please let me know.
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From: Fangyu Yu fangyu.yu@linux.alibaba.com
[ Upstream commit 2b351e3d04be9e1533f26c3464f1e44a5beace30 ]
According to the RISC-V Privileged Architecture Spec, when MODE=Bare is selected,software must write zero to the remaining fields of hgatp.
We have detected the valid mode supported by the HW before, So using a valid mode to detect how many vmid bits are supported.
Fixes: fd7bb4a251df ("RISC-V: KVM: Implement VMID allocator") Reviewed-by: Nutty Liu nutty.liu@hotmail.com Reviewed-by: Troy Mitchell troy.mitchell@linux.spacemit.com Reviewed-by: Guo Ren (Alibaba DAMO Academy) guoren@kernel.org Signed-off-by: Fangyu Yu fangyu.yu@linux.alibaba.com Signed-off-by: Guo Ren (Alibaba DAMO Academy) guoren@kernel.org Link: https://lore.kernel.org/r/20250821142542.2472079-2-guoren@kernel.org Signed-off-by: Anup Patel anup@brainfault.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kvm/vmid.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c index 3b426c800480c..5f33625f40706 100644 --- a/arch/riscv/kvm/vmid.c +++ b/arch/riscv/kvm/vmid.c @@ -14,6 +14,7 @@ #include <linux/smp.h> #include <linux/kvm_host.h> #include <asm/csr.h> +#include <asm/kvm_mmu.h> #include <asm/kvm_tlb.h> #include <asm/kvm_vmid.h>
@@ -28,7 +29,7 @@ void __init kvm_riscv_gstage_vmid_detect(void)
/* Figure-out number of VMID bits in HW */ old = csr_read(CSR_HGATP); - csr_write(CSR_HGATP, old | HGATP_VMID); + csr_write(CSR_HGATP, (kvm_riscv_gstage_mode << HGATP_MODE_SHIFT) | HGATP_VMID); vmid_bits = csr_read(CSR_HGATP); vmid_bits = (vmid_bits & HGATP_VMID) >> HGATP_VMID_SHIFT; vmid_bits = fls_long(vmid_bits);