x86, vmi: Mark VMI deprecated and schedule it for removal

Add text in feature-removal.txt indicating that VMI will be removed in
the 2.6.37 timeframe.

Signed-off-by: Alok N Kataria <akataria@vmware.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
LKML-Reference: <1254193238.13456.48.camel@ank32.eng.vmware.com>
[ removed a bogus Kconfig change, marked (DEPRECATED) in Kconfig ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 89a47b5..04e6c81 100644 (file)
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -451,3 +451,33 @@ Why:       OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
        will also allow making ALSA OSS emulation independent of
        sound_core.  The dependency will be broken then too.
 Who:   Tejun Heo <tj@kernel.org>
+
+----------------------------
+
+What:  Support for VMware's guest paravirtuliazation technique [VMI] will be
+       dropped.
+When:  2.6.37 or earlier.
+Why:   With the recent innovations in CPU hardware acceleration technologies
+       from Intel and AMD, VMware ran a few experiments to compare these
+       techniques to guest paravirtualization technique on VMware's platform.
+       These hardware assisted virtualization techniques have outperformed the
+       performance benefits provided by VMI in most of the workloads. VMware
+       expects that these hardware features will be ubiquitous in a couple of
+       years, as a result, VMware has started a phased retirement of this
+       feature from the hypervisor. We will be removing this feature from the
+       Kernel too. Right now we are targeting 2.6.37 but can retire earlier if
+       technical reasons (read opportunity to remove major chunk of pvops)
+       arise.
+
+       Please note that VMI has always been an optimization and non-VMI kernels
+       still work fine on VMware's platform.
+       Latest versions of VMware's product which support VMI are,
+       Workstation 7.0 and VSphere 4.0 on ESX side, future maintainence
+       releases for these products will continue supporting VMI.
+
+       For more details about VMI retirement take a look at this,
+       http://blogs.vmware.com/guestosguide/2009/09/vmi-retirement.html
+
+Who:   Alok N Kataria <akataria@vmware.com>
+
+----------------------------

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c876bac..07e0114 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -491,7 +491,7 @@ if PARAVIRT_GUEST
 source "arch/x86/xen/Kconfig"
 
 config VMI
-       bool "VMI Guest support"
+       bool "VMI Guest support (DEPRECATED)"
        select PARAVIRT
        depends on X86_32
        ---help---
@@ -500,6 +500,15 @@ config VMI
          at the moment), by linking the kernel to a GPL-ed ROM module
          provided by the hypervisor.
 
+         As of September 2009, VMware has started a phased retirement
+         of this feature from VMware's products. Please see
+         feature-removal-schedule.txt for details.  If you are
+         planning to enable this option, please note that you cannot
+         live migrate a VMI enabled VM to a future VMware product,
+         which doesn't support VMI. So if you expect your kernel to
+         seamlessly migrate to newer VMware products, keep this
+         disabled.
+
 config KVM_CLOCK
        bool "KVM paravirtualized clock"
        select PARAVIRT

diff --git a/arch/x86/kernel/vmi_32.c b/arch/x86/kernel/vmi_32.c
index 31e6f6c..d430e4c 100644 (file)
--- a/arch/x86/kernel/vmi_32.c
+++ b/arch/x86/kernel/vmi_32.c
@@ -648,7 +648,7 @@ static inline int __init activate_vmi(void)
 
        pv_info.paravirt_enabled = 1;
        pv_info.kernel_rpl = kernel_cs & SEGMENT_RPL_MASK;
-       pv_info.name = "vmi";
+       pv_info.name = "vmi [deprecated]";
 
        pv_init_ops.patch = vmi_patch;