diff options
Diffstat (limited to 'arch/ia64/kvm/kvm_fw.c')
| -rw-r--r-- | arch/ia64/kvm/kvm_fw.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/arch/ia64/kvm/kvm_fw.c b/arch/ia64/kvm/kvm_fw.c index a8ae52ed5635..e4b82319881d 100644 --- a/arch/ia64/kvm/kvm_fw.c +++ b/arch/ia64/kvm/kvm_fw.c @@ -21,6 +21,9 @@ #include <linux/kvm_host.h> #include <linux/smp.h> +#include <asm/sn/addrs.h> +#include <asm/sn/clksupport.h> +#include <asm/sn/shub_mmr.h> #include "vti.h" #include "misc.h" @@ -188,12 +191,35 @@ static struct ia64_pal_retval pal_freq_base(struct kvm_vcpu *vcpu) return result; } -static struct ia64_pal_retval pal_freq_ratios(struct kvm_vcpu *vcpu) +/* + * On the SGI SN2, the ITC isn't stable. Emulation backed by the SN2 + * RTC is used instead. This function patches the ratios from SAL + * to match the RTC before providing them to the guest. + */ +static void sn2_patch_itc_freq_ratios(struct ia64_pal_retval *result) { + struct pal_freq_ratio *ratio; + unsigned long sal_freq, sal_drift, factor; + + result->status = ia64_sal_freq_base(SAL_FREQ_BASE_PLATFORM, + &sal_freq, &sal_drift); + ratio = (struct pal_freq_ratio *)&result->v2; + factor = ((sal_freq * 3) + (sn_rtc_cycles_per_second / 2)) / + sn_rtc_cycles_per_second; + + ratio->num = 3; + ratio->den = factor; +} +static struct ia64_pal_retval pal_freq_ratios(struct kvm_vcpu *vcpu) +{ struct ia64_pal_retval result; PAL_CALL(result, PAL_FREQ_RATIOS, 0, 0, 0); + + if (vcpu->kvm->arch.is_sn2) + sn2_patch_itc_freq_ratios(&result); + return result; } |