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authorKonstantin Ozerkov <kozerkov@parallels.com>2011-11-09 19:28:55 +0400
committerTakashi Iwai <tiwai@suse.de>2011-11-09 21:34:28 +0400
commit7fb4f392bd27e5b0e2444430d241370837bcc8fa (patch)
treea7488f66f50f8469919e78865a25a781b06547d0 /sound/pci/intel8x0.c
parent65c397d6b58d5e401bee7c24608d3a33a220a63a (diff)
downloadlinux-7fb4f392bd27e5b0e2444430d241370837bcc8fa.tar.xz
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: Konstantin Ozerkov <kozerkov@parallels.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/pci/intel8x0.c')
-rw-r--r--sound/pci/intel8x0.c41
1 files changed, 31 insertions, 10 deletions
diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c
index 2d4bb4c9a030..11718b49b2e2 100644
--- a/sound/pci/intel8x0.c
+++ b/sound/pci/intel8x0.c
@@ -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;
+ 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;
}
@@ -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)