diff options
| -rw-r--r-- | arch/x86/kernel/amd_nb.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c index 11fac09e3a8c..67e773744edb 100644 --- a/arch/x86/kernel/amd_nb.c +++ b/arch/x86/kernel/amd_nb.c @@ -143,7 +143,6 @@ bool __init early_is_amd_nb(u32 device) struct resource *amd_get_mmconfig_range(struct resource *res) { - u32 address; u64 base, msr; unsigned int segn_busn_bits; @@ -151,13 +150,11 @@ struct resource *amd_get_mmconfig_range(struct resource *res) boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) return NULL; - /* assume all cpus from fam10h have mmconfig */ - if (boot_cpu_data.x86 < 0x10) + /* Assume CPUs from Fam10h have mmconfig, although not all VMs do */ + if (boot_cpu_data.x86 < 0x10 || + rdmsrl_safe(MSR_FAM10H_MMIO_CONF_BASE, &msr)) return NULL; - address = MSR_FAM10H_MMIO_CONF_BASE; - rdmsrl(address, msr); - /* mmconfig is not enabled */ if (!(msr & FAM10H_MMIO_CONF_ENABLE)) return NULL; |