Patchwork [v3,06/17] SUPPORT.md: Add scalability features

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Submitter George Dunlap
Date Nov. 22, 2017, 7:20 p.m.
Message ID <20171122192024.21187-6-george.dunlap@citrix.com>
Download mbox | patch
Permalink /patch/388289/
State New
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George Dunlap - Nov. 22, 2017, 7:20 p.m.
Superpage support and PVHVM.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
---
Changes since v2:
- Reworked superpage section

CC: Ian Jackson <ian.jackson@citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Jan Beulich <jbeulich@suse.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Konrad Wilk <konrad.wilk@oracle.com>
CC: Tim Deegan <tim@xen.org>
CC: Julien Grall <julien.grall@arm.com>
---
 SUPPORT.md | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

Patch

diff --git a/SUPPORT.md b/SUPPORT.md
index df429cb3c4..dd3632b913 100644
--- a/SUPPORT.md
+++ b/SUPPORT.md
@@ -196,6 +196,33 @@  on embedded platforms.
 
 Enables NUMA aware scheduling in Xen
 
+## Scalability
+
+### Super page support
+
+    Status, x86 HVM/PVH, HAP: Supported
+    Status, x86 HVM/PVH, Shadow, 2MiB: Supported
+    Status, ARM: Supported
+
+NB that this refers to the ability of guests
+to have higher-level page table entries point directly to memory,
+improving TLB performance.
+On ARM, and on x86 in HAP mode,
+the guest has whatever support is enabled by the hardware.
+On x86 in shadow mode, only 2MiB (L2) superpages are available;
+furthermore, they do not have the performance characteristics of hardware superpages.
+
+Also note is feature independent of the ARM "page granularity" feature (see below).
+
+### x86/PVHVM
+
+    Status: Supported
+
+This is a useful label for a set of hypervisor features
+which add paravirtualized functionality to HVM guests
+for improved performance and scalability.
+This includes exposing event channels to HVM guests.
+
 # Format and definitions
 
 This file contains prose, and machine-readable fragments.