riscv: KVM: Fix hart suspend_type use

[ Upstream commit e3219b0c491f2aa0e0b200a39d3352ab05cdda96 ]

The spec says suspend_type is 32 bits wide and "In case the data is
defined as 32bit wide, higher privilege software must ensure that it
only uses 32 bit data." Mask off upper bits of suspend_type before
using it.

Fixes: 763c8bed8c05 ("RISC-V: KVM: Implement SBI HSM suspend call")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20250217084506.18763-9-ajones@ventanamicro.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/riscv/kvm/vcpu_sbi_hsm.c b/arch/riscv/kvm/vcpu_sbi_hsm.c
index 13a35eb77e8e353ae66f8832f78ec549df6fd892..3070bb31745de7642d09480e6e2ed48c3023a04c 100644 (file)
--- a/arch/riscv/kvm/vcpu_sbi_hsm.c
+++ b/arch/riscv/kvm/vcpu_sbi_hsm.c
@@ -9,6 +9,7 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/kvm_host.h>
+#include <linux/wordpart.h>
 #include <asm/sbi.h>
 #include <asm/kvm_vcpu_sbi.h>
 
@@ -109,7 +110,7 @@ static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
                }
                return 0;
        case SBI_EXT_HSM_HART_SUSPEND:
-               switch (cp->a0) {
+               switch (lower_32_bits(cp->a0)) {
                case SBI_HSM_SUSPEND_RET_DEFAULT:
                        kvm_riscv_vcpu_wfi(vcpu);
                        break;