Re: Paravirtualization on VMware's Platform [VMI].
From: Alok Kataria <hidden>
Date: 2009-09-29 17:25:22
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On Tue, 2009-09-29 at 02:01 -0700, Chris Wright wrote:
* Alok Kataria (akataria@vmware.com) wrote:quoted
On Mon, 2009-09-28 at 19:25 -0700, H. Peter Anvin wrote:quoted
On 09/28/2009 05:45 PM, Alok Kataria wrote:quoted
+ bool "VMI Guest support [will be deprecated soon]" + default nThis is incorrect use of the word "deprecated"... it's *already* deprecated (a word which pretty much means the opposite of "recommended".) As far as "default n" is concerned... this is usually not necessary; "n" is the default unless anything else is specified.How about this ? Thanks.Looks good to me (missing Signed-off-by). I think it's also useful to generate some runtime noise saying it's a deprecated option. Even something as simple as: - pv_info.name = "vmi" + pv_info.name = "vmi [deprecated]";
Yep, I was thinking of adding KERN_WARN's in vmi_init, though I like your suggestion better. Also added SOB line. Thanks. -- Mark VMI for removal in feature-removal-schedule.txt. From: Alok N Kataria <redacted> Add text in feature-removal.txt and also modify Kconfig to disable vmi by default. Signed-off-by: Alok N Kataria <redacted> --- Documentation/feature-removal-schedule.txt | 30 ++++++++++++++++++++++++++++ arch/x86/Kconfig | 12 ++++++++--- arch/x86/kernel/vmi_32.c | 2 +- 3 files changed, 40 insertions(+), 4 deletions(-)
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 89a47b5..04e6c81 100644
--- 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 f777aaf..44c1660 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig@@ -496,14 +496,20 @@ if PARAVIRT_GUEST source "arch/x86/xen/Kconfig" config VMI - bool "VMI Guest support" - select PARAVIRT - depends on X86_32 + bool "VMI Guest support [deprecated]" + depends on X86_32 && PARAVIRT ---help--- VMI provides a paravirtualized interface to the VMware ESX server (it could be used by other hypervisors in theory too, but is not 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"
diff --git a/arch/x86/kernel/vmi_32.c b/arch/x86/kernel/vmi_32.c
index 31e6f6c..d430e4c 100644
--- 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;