[xen staging] x86/cpuid: Move VMX/SVM out of the default policy

[patchbot@xxxxxxx]

commit 35679b221ee731a957f180051ede70ef49bb4fe0
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Wed Sep 30 10:17:33 2020 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Tue Oct 6 12:28:37 2020 +0100

    x86/cpuid: Move VMX/SVM out of the default policy
    
    Nested virt is still experimental, and requires explicitly opting in to at
    domain create time.  The VMX/SVM features should not be visible by default.
    
    Also correct them from all HVM guests, to just HAP-enabled guests.  This has
    been the restriction for SVM right from the outset (c/s e006a0e0aaa), while
    VMX was first introduced supporting shadow mode (c/s 9122c69c8d3) but later
    adjusted to HAP-only (c/s 77751ed79e3).
    
    There is deliberately no adjustment to xc_cpuid_apply_policy() for pre-4.14
    migration compatibility.  The migration stream doesn't contain the required
    architectural state for either VMX/SVM, and a nested virt VM which migrates
    will explode in weird and wonderful ways.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/include/public/arch-x86/cpufeatureset.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/include/public/arch-x86/cpufeatureset.h 
b/xen/include/public/arch-x86/cpufeatureset.h
index abd18722ee..ef7cca334d 100644
--- a/xen/include/public/arch-x86/cpufeatureset.h
+++ b/xen/include/public/arch-x86/cpufeatureset.h
@@ -127,7 +127,7 @@ XEN_CPUFEATURE(PCLMULQDQ,     1*32+ 1) /*A  Carry-less 
multiplication */
 XEN_CPUFEATURE(DTES64,        1*32+ 2) /*   64-bit Debug Store */
 XEN_CPUFEATURE(MONITOR,       1*32+ 3) /*   Monitor/Mwait support */
 XEN_CPUFEATURE(DSCPL,         1*32+ 4) /*   CPL Qualified Debug Store */
-XEN_CPUFEATURE(VMX,           1*32+ 5) /*S  Virtual Machine Extensions */
+XEN_CPUFEATURE(VMX,           1*32+ 5) /*h  Virtual Machine Extensions */
 XEN_CPUFEATURE(SMX,           1*32+ 6) /*   Safer Mode Extensions */
 XEN_CPUFEATURE(EIST,          1*32+ 7) /*   Enhanced SpeedStep */
 XEN_CPUFEATURE(TM2,           1*32+ 8) /*   Thermal Monitor 2 */
@@ -166,7 +166,7 @@ XEN_CPUFEATURE(3DNOW,         2*32+31) /*A  3DNow! */
 /* AMD-defined CPU features, CPUID level 0x80000001.ecx, word 3 */
 XEN_CPUFEATURE(LAHF_LM,       3*32+ 0) /*A  LAHF/SAHF in long mode */
 XEN_CPUFEATURE(CMP_LEGACY,    3*32+ 1) /*!A If yes HyperThreading not valid */
-XEN_CPUFEATURE(SVM,           3*32+ 2) /*S  Secure virtual machine */
+XEN_CPUFEATURE(SVM,           3*32+ 2) /*h  Secure virtual machine */
 XEN_CPUFEATURE(EXTAPIC,       3*32+ 3) /*   Extended APIC space */
 XEN_CPUFEATURE(CR8_LEGACY,    3*32+ 4) /*S  CR8 in 32-bit mode */
 XEN_CPUFEATURE(ABM,           3*32+ 5) /*A  Advanced bit manipulation */
--
generated by git-patchbot for /home/xen/git/xen.git#staging