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author | Daniel Henrique Barboza <dbarboza@ventanamicro.com> | 2023-08-02 15:00:58 -0300 |
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committer | Alistair Francis <alistair.francis@wdc.com> | 2023-08-11 14:16:26 -0400 |
commit | 136cb9cc03154615609d454db40e0b3dfbb4bbf3 (patch) | |
tree | 8c4cee436105212547f541f5bb3d6b441c757885 /target/riscv | |
parent | 3944e93af06f06eb07316e0bef46b007573e0309 (diff) | |
download | qemu-136cb9cc03154615609d454db40e0b3dfbb4bbf3.zip qemu-136cb9cc03154615609d454db40e0b3dfbb4bbf3.tar.gz qemu-136cb9cc03154615609d454db40e0b3dfbb4bbf3.tar.bz2 |
target/riscv/kvm.c: fix mvendorid size in vcpu_set_machine_ids()
cpu->cfg.mvendorid is a 32 bit field and kvm_set_one_reg() always write
a target_ulong val, i.e. a 64 bit field in a 64 bit host.
Given that we're passing a pointer to the mvendorid field, the reg is
reading 64 bits starting from mvendorid and going 32 bits in the next
field, marchid. Here's an example:
$ ./qemu-system-riscv64 -machine virt,accel=kvm -m 2G -smp 1 \
-cpu rv64,marchid=0xab,mvendorid=0xcd,mimpid=0xef(...)
(inside the guest)
# cat /proc/cpuinfo
processor : 0
hart : 0
isa : rv64imafdc_zicbom_zicboz_zihintpause_zbb_sstc
mmu : sv57
mvendorid : 0xab000000cd
marchid : 0xab
mimpid : 0xef
'mvendorid' was written as a combination of 0xab (the value from the
adjacent field, marchid) and its intended value 0xcd.
Fix it by assigning cpu->cfg.mvendorid to a target_ulong var 'reg' and
use it as input for kvm_set_one_reg(). Here's the result with this patch
applied and using the same QEMU command line:
# cat /proc/cpuinfo
processor : 0
hart : 0
isa : rv64imafdc_zicbom_zicboz_zihintpause_zbb_sstc
mmu : sv57
mvendorid : 0xcd
marchid : 0xab
mimpid : 0xef
This bug affects only the generic (rv64) CPUs when running with KVM in a
64 bit env since the 'host' CPU does not allow the machine IDs to be
changed via command line.
Fixes: 1fb5a622f7 ("target/riscv: handle mvendorid/marchid/mimpid for KVM CPUs")
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20230802180058.281385-1-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Diffstat (limited to 'target/riscv')
-rw-r--r-- | target/riscv/kvm.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c index 9d8a898..b1fd223 100644 --- a/target/riscv/kvm.c +++ b/target/riscv/kvm.c @@ -852,12 +852,19 @@ void kvm_arch_init_irq_routing(KVMState *s) static int kvm_vcpu_set_machine_ids(RISCVCPU *cpu, CPUState *cs) { CPURISCVState *env = &cpu->env; + target_ulong reg; uint64_t id; int ret; id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG, KVM_REG_RISCV_CONFIG_REG(mvendorid)); - ret = kvm_set_one_reg(cs, id, &cpu->cfg.mvendorid); + /* + * cfg.mvendorid is an uint32 but a target_ulong will + * be written. Assign it to a target_ulong var to avoid + * writing pieces of other cpu->cfg fields in the reg. + */ + reg = cpu->cfg.mvendorid; + ret = kvm_set_one_reg(cs, id, ®); if (ret != 0) { return ret; } |