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Diffstat (limited to 'sound/pci/intel8x0.c')
-rw-r--r--sound/pci/intel8x0.c58
1 files changed, 47 insertions, 11 deletions
diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c
index 29e312597f2..11718b49b2e 100644
--- a/sound/pci/intel8x0.c
+++ b/sound/pci/intel8x0.c
@@ -1077,6 +1077,13 @@ static snd_pcm_uframes_t snd_intel8x0_pcm_pointer(struct snd_pcm_substream *subs
}
if (civ != igetbyte(chip, ichdev->reg_offset + ICH_REG_OFF_CIV))
continue;
+
+ /* IO read operation is very expensive inside virtual machine
+ * as it is emulated. The probability that subsequent PICB read
+ * will return different result is high enough to loop till
+ * timeout here.
+ * Same CIV is strict enough condition to be sure that PICB
+ * is valid inside VM on emulated card. */
if (chip->inside_vm)
break;
if (ptr1 == igetword(chip, ichdev->reg_offset + ichdev->roff_picb))
@@ -2930,6 +2937,45 @@ static unsigned int sis_codec_bits[3] = {
ICH_PCR, ICH_SCR, ICH_SIS_TCR
};
+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;
+ }
+
+ /* 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;
+ }
+
+fini:
+ if (msg != NULL)
+ printk(KERN_INFO "intel8x0: %s optimization\n", msg);
+
+ return result;
+}
+
static int __devinit snd_intel8x0_create(struct snd_card *card,
struct pci_dev *pci,
unsigned long device_type,
@@ -2997,9 +3043,7 @@ static int __devinit snd_intel8x0_create(struct snd_card *card,
if (xbox)
chip->xbox = 1;
- chip->inside_vm = inside_vm;
- if (inside_vm)
- printk(KERN_INFO "intel8x0: enable KVM optimization\n");
+ chip->inside_vm = snd_intel8x0_inside_vm(pci);
if (pci->vendor == PCI_VENDOR_ID_INTEL &&
pci->device == PCI_DEVICE_ID_INTEL_440MX)
@@ -3243,14 +3287,6 @@ static int __devinit snd_intel8x0_probe(struct pci_dev *pci,
buggy_irq = 0;
}
- if (inside_vm < 0) {
- /* detect KVM and Parallels virtual environments */
- inside_vm = kvm_para_available();
-#if defined(__i386__) || defined(__x86_64__)
- inside_vm = inside_vm || boot_cpu_has(X86_FEATURE_HYPERVISOR);
-#endif
- }
-
if ((err = snd_intel8x0_create(card, pci, pci_id->driver_data,
&chip)) < 0) {
snd_card_free(card);