From 7fb4f392bd27e5b0e2444430d241370837bcc8fa Mon Sep 17 00:00:00 2001 From: Konstantin Ozerkov Date: Wed, 9 Nov 2011 19:28:55 +0400 Subject: [PATCH] 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 Signed-off-by: Denis V. Lunev Signed-off-by: Takashi Iwai --- sound/pci/intel8x0.c | 43 ++++++++++++++++++++++++++++++++----------- 1 file changed, 32 insertions(+), 11 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); -#endif + /* check module parameter first (override detection) */ + if (result >= 0) { + msg = result ? "enable (forced) VM" : "disable (forced) VM"; + goto fini; } - if (result) - printk(KERN_INFO "intel8x0: enable KVM optimization\n"); + /* 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; } @@ -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)