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Commit 7fb4f392 authored by Konstantin Ozerkov's avatar Konstantin Ozerkov Committed by Takashi Iwai
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ALSA: intel8x0: improve virtual environment detection 



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.

[ fixed a minor coding-style issue by tiwai]

Signed-off-by: default avatarKonstantin Ozerkov <kozerkov@parallels.com>
Signed-off-by: default avatarDenis V. Lunev <den@openvz.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 65c397d6

sound/pci/intel8x0.c

+31 −10
Original line number Diff line number Diff line
@@ -2937,20 +2937,41 @@ 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;

	char *msg   = NULL;



	/* check module parameter first (override detection) */

	if (result >= 0) {

		msg = result ? "enable (forced) VM" : "disable (forced) VM";

		goto fini;

	}



	if (result < 0) {

	/* detect KVM and Parallels virtual environments */

	result = kvm_para_available();

#if defined(__i386__) || defined(__x86_64__)

#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;

}
@@ -3022,7 +3043,7 @@ 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)