This patch cleans and simplifies kvm_dev_ioctl_get_supported_cpuid by using a table instead of duplicating code as Avi suggested.
This patch also fixes a bug where kvm_dev_ioctl_get_supported_cpuid would return -E2BIG when amount of entries passed was just right. Cc: Avi Kivity <[email protected]> Cc: Marcelo Tosatti <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- arch/x86/kvm/cpuid.c | 78 ++++++++++++++++++++++--------------------------- 1 files changed, 35 insertions(+), 43 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index bbaa6d8..c9ede4d 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -425,12 +425,31 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, #undef F +struct kvm_cpuid_param { + u32 func; + u32 idx; + u32 leaves; + int (*qualifier)(struct kvm_cpuid_param *param); +}; + +int is_centaur_cpu(struct kvm_cpuid_param *param) +{ + return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; +} + int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries) { struct kvm_cpuid_entry2 *cpuid_entries; - int limit, nent = 0, r = -E2BIG; + int limit, nent = 0, r = -E2BIG, i; u32 func; + struct kvm_cpuid_param param[] = { + { .func = 0, .leaves = 1 }, + { .func = 0x80000000, .leaves = 1 }, + { .func = 0xC0000000, .qualifier = is_centaur_cpu, .leaves = 1 }, + { .func = KVM_CPUID_SIGNATURE }, + { .func = KVM_CPUID_FEATURES }, + }; if (cpuid->nent < 1) goto out; @@ -441,59 +460,32 @@ int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid, if (!cpuid_entries) goto out; - do_cpuid_ent(&cpuid_entries[0], 0, 0, &nent, cpuid->nent); - limit = cpuid_entries[0].eax; - for (func = 1; func <= limit && nent < cpuid->nent; ++func) - do_cpuid_ent(&cpuid_entries[nent], func, 0, - &nent, cpuid->nent); - r = -E2BIG; - if (nent >= cpuid->nent) - goto out_free; - - do_cpuid_ent(&cpuid_entries[nent], 0x80000000, 0, &nent, cpuid->nent); - limit = cpuid_entries[nent - 1].eax; - for (func = 0x80000001; func <= limit && nent < cpuid->nent; ++func) - do_cpuid_ent(&cpuid_entries[nent], func, 0, - &nent, cpuid->nent); - + for (i = 0; i < ARRAY_SIZE(param); i++) { + struct kvm_cpuid_param *ent = ¶m[i]; + if (ent->qualifier && !ent->qualifier(ent)) + continue; - r = -E2BIG; - if (nent >= cpuid->nent) - goto out_free; + if (nent >= cpuid->nent) + break; - /* Add support for Centaur's CPUID instruction. */ - if (boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR) { - do_cpuid_ent(&cpuid_entries[nent], 0xC0000000, 0, + do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, &nent, cpuid->nent); - r = -E2BIG; - if (nent >= cpuid->nent) - goto out_free; + if (!ent->leaves) + continue; limit = cpuid_entries[nent - 1].eax; - for (func = 0xC0000001; - func <= limit && nent < cpuid->nent; ++func) - do_cpuid_ent(&cpuid_entries[nent], func, 0, - &nent, cpuid->nent); + for (func = ent->func + 1; func <= limit && nent < cpuid->nent; ++func) + do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, + &nent, cpuid->nent); - r = -E2BIG; - if (nent >= cpuid->nent) - goto out_free; + if (func <= limit) + break; } - do_cpuid_ent(&cpuid_entries[nent], KVM_CPUID_SIGNATURE, 0, &nent, - cpuid->nent); - - r = -E2BIG; - if (nent >= cpuid->nent) - goto out_free; - - do_cpuid_ent(&cpuid_entries[nent], KVM_CPUID_FEATURES, 0, &nent, - cpuid->nent); - r = -E2BIG; - if (nent >= cpuid->nent) + if (i < ARRAY_SIZE(param) || nent > cpuid->nent) goto out_free; r = -EFAULT; -- 1.7.8.rc3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
