On Tue, 2021-05-04 at 10:17 -0700, Sean Christopherson wrote:
> Split out and export the number of configured user return MSRs so that
> VMX can iterate over the set of MSRs without having to do its own tracking.
> Keep the list itself internal to x86 so that vendor code still has to go
> through the "official" APIs to add/modify entries.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/include/asm/kvm_host.h | 1 +
> arch/x86/kvm/x86.c | 29 +++++++++++++----------------
> 2 files changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index c9452472ed55..10663610f105 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1419,6 +1419,7 @@ struct kvm_arch_async_pf {
> bool direct_map;
> };
>
> +extern u32 __read_mostly kvm_nr_uret_msrs;
> extern u64 __read_mostly host_efer;
> extern bool __read_mostly allow_smaller_maxphyaddr;
> extern struct kvm_x86_ops kvm_x86_ops;
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 90ef340565a4..2fd46e917666 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -184,11 +184,6 @@ module_param(pi_inject_timer, bint, S_IRUGO | S_IWUSR);
> */
> #define KVM_MAX_NR_USER_RETURN_MSRS 16
>
> -struct kvm_user_return_msrs_global {
> - int nr;
> - u32 msrs[KVM_MAX_NR_USER_RETURN_MSRS];
> -};
> -
> struct kvm_user_return_msrs {
> struct user_return_notifier urn;
> bool registered;
> @@ -198,7 +193,9 @@ struct kvm_user_return_msrs {
> } values[KVM_MAX_NR_USER_RETURN_MSRS];
> };
>
> -static struct kvm_user_return_msrs_global __read_mostly user_return_msrs_global;
> +u32 __read_mostly kvm_nr_uret_msrs;
> +EXPORT_SYMBOL_GPL(kvm_nr_uret_msrs);
> +static u32 __read_mostly kvm_uret_msrs_list[KVM_MAX_NR_USER_RETURN_MSRS];
> static struct kvm_user_return_msrs __percpu *user_return_msrs;
>
> #define KVM_SUPPORTED_XCR0 (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \
> @@ -330,10 +327,10 @@ static void kvm_on_user_return(struct user_return_notifier *urn)
> user_return_notifier_unregister(urn);
> }
> local_irq_restore(flags);
> - for (slot = 0; slot < user_return_msrs_global.nr; ++slot) {
> + for (slot = 0; slot < kvm_nr_uret_msrs; ++slot) {
> values = &msrs->values[slot];
> if (values->host != values->curr) {
> - wrmsrl(user_return_msrs_global.msrs[slot], values->host);
> + wrmsrl(kvm_uret_msrs_list[slot], values->host);
> values->curr = values->host;
> }
> }
> @@ -358,9 +355,9 @@ EXPORT_SYMBOL_GPL(kvm_probe_user_return_msr);
> void kvm_define_user_return_msr(unsigned slot, u32 msr)
> {
> BUG_ON(slot >= KVM_MAX_NR_USER_RETURN_MSRS);
> - user_return_msrs_global.msrs[slot] = msr;
> - if (slot >= user_return_msrs_global.nr)
> - user_return_msrs_global.nr = slot + 1;
> + kvm_uret_msrs_list[slot] = msr;
> + if (slot >= kvm_nr_uret_msrs)
> + kvm_nr_uret_msrs = slot + 1;
> }
> EXPORT_SYMBOL_GPL(kvm_define_user_return_msr);
>
> @@ -368,8 +365,8 @@ int kvm_find_user_return_msr(u32 msr)
> {
> int i;
>
> - for (i = 0; i < user_return_msrs_global.nr; ++i) {
> - if (user_return_msrs_global.msrs[i] == msr)
> + for (i = 0; i < kvm_nr_uret_msrs; ++i) {
> + if (kvm_uret_msrs_list[i] == msr)
> return i;
> }
> return -1;
> @@ -383,8 +380,8 @@ static void kvm_user_return_msr_cpu_online(void)
> u64 value;
> int i;
>
> - for (i = 0; i < user_return_msrs_global.nr; ++i) {
> - rdmsrl_safe(user_return_msrs_global.msrs[i], &value);
> + for (i = 0; i < kvm_nr_uret_msrs; ++i) {
> + rdmsrl_safe(kvm_uret_msrs_list[i], &value);
> msrs->values[i].host = value;
> msrs->values[i].curr = value;
> }
> @@ -399,7 +396,7 @@ int kvm_set_user_return_msr(unsigned slot, u64 value, u64 mask)
> value = (value & mask) | (msrs->values[slot].host & ~mask);
> if (value == msrs->values[slot].curr)
> return 0;
> - err = wrmsrl_safe(user_return_msrs_global.msrs[slot], value);
> + err = wrmsrl_safe(kvm_uret_msrs_list[slot], value);
> if (err)
> return 1;
>
Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Best regards,
Maxim Levitsky
