Detection code improved by PCI SSID usage. VM optimization now enabled only for known devcices (skip host devices forwarded to VM by VT-d or same kind of technology). For debug/troubleshooting purposes optimization can be forced (on/off) by module parameter: "inside_vm" (boolean).
Known devices (PCI SSID): 1af4:1100: Reserved for KVM devices. Note this is not yet implemented for KVM's ICH/AC'97 emulation. 1ab8:xxxx: Parallels ICH/AC'97 emulated sound.
Signed-off-by: Konstantin Ozerkov kozerkov@parallels.com Signed-off-by: Denis V. Lunev den@openvz.org
diff --git a/pci/intel8x0.c b/pci/intel8x0.c index d726d94..7db2a74 100644 --- a/pci/intel8x0.c +++ b/pci/intel8x0.c @@ -2930,20 +2930,41 @@ static unsigned int sis_codec_bits[3] = { ICH_PCR, ICH_SCR, ICH_SIS_TCR };
-static int __devinit snd_intel8x0_inside_vm(void) +static int __devinit snd_intel8x0_inside_vm(struct pci_dev *pci) { - int result = inside_vm; + int result = inside_vm; + char* msg = NULL;
- if (result < 0) { - /* detect KVM and Parallels virtual environments */ - result = kvm_para_available(); -#if defined(__i386__) || defined(__x86_64__) - result = result || boot_cpu_has(X86_FEATURE_HYPERVISOR); + /* check module parameter first (override detection) */ + if (result >= 0) { + msg = result ? "enable (forced) VM" : "disable (forced) VM"; + goto fini; + } + + /* detect KVM and Parallels virtual environments */ + result = kvm_para_available(); +#ifdef X86_FEATURE_HYPERVISOR + result = result || boot_cpu_has(X86_FEATURE_HYPERVISOR); #endif + if (!result) + goto fini; + + /* check for known (emulated) devices */ + if (pci->subsystem_vendor == 0x1af4 && + pci->subsystem_device == 0x1100) { + /* KVM emulated sound, PCI SSID: 1af4:1100 */ + msg = "enable KVM"; + } else if (pci->subsystem_vendor == 0x1ab8) { + /* Parallels VM emulated sound, PCI SSID: 1ab8:xxxx */ + msg = "enable Parallels VM"; + } else { + msg = "disable (unknown or VT-d) VM"; + result = 0; }
- if (result) - printk(KERN_INFO "intel8x0: enable KVM optimization\n"); +fini: + if (msg != NULL) + printk(KERN_INFO "intel8x0: %s optimization\n", msg);
return result; } @@ -3015,7 +3036,7 @@ static int __devinit snd_intel8x0_create(struct snd_card *card, if (xbox) chip->xbox = 1;
- chip->inside_vm = snd_intel8x0_inside_vm(); + chip->inside_vm = snd_intel8x0_inside_vm(pci);
if (pci->vendor == PCI_VENDOR_ID_INTEL && pci->device == PCI_DEVICE_ID_INTEL_440MX)