[PATCH v2 04/10] x86/cpu-policy: MSR_ARCH_CAPS feature names

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Seed the default visibility from the dom0 special case, which for the most
part just exposes the *_NO bits.  EIBRS is the one non-*_NO bit, which is
"just" a status bit to the guest indicating a change in implemention of IBRS
which is already fully supported.

Insert a block dependency from the ARCH_CAPS CPUID bit to the entire content
of the MSR.  This is because MSRs have no structure information similar to
CPUID, and used by x86_cpu_policy_clear_out_of_range_leaves(), in order to
bulk-clear inaccessable words.

The overall CPUID bit is still max-only, so all of MSR_ARCH_CAPS is hidden in
the default policies.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>

There is no libxl logic because libxl still uses the older xend format which
is specific to CPUID data.  That is going to need untangling at some other
point.

v2:
 * Don't expose SKIP_L1DFL to guests (it's only applicable for nested virt)
 * Fix SBDR_SSDP_NO and FBSDP_NO names.
 * Extend the commit message.
---
 tools/misc/xen-cpuid.c                      | 13 ++++++++++++
 xen/include/public/arch-x86/cpufeatureset.h | 23 +++++++++++++++++++++
 xen/tools/gen-cpuid.py                      |  3 +++
 3 files changed, 39 insertions(+)

diff --git a/tools/misc/xen-cpuid.c b/tools/misc/xen-cpuid.c
index 15ad2d33e2a1..8925a583edd5 100644
--- a/tools/misc/xen-cpuid.c
+++ b/tools/misc/xen-cpuid.c
@@ -228,6 +228,19 @@ static const char *const str_7d2[32] =
 
 static const char *const str_10Al[32] =
 {
+    [ 0] = "rdcl-no",             [ 1] = "eibrs",
+    [ 2] = "rsba",                [ 3] = "skip-l1dfl",
+    [ 4] = "intel-ssb-no",        [ 5] = "mds-no",
+    [ 6] = "if-pschange-mc-no",   [ 7] = "tsx-ctrl",
+    [ 8] = "taa-no",              [ 9] = "mcu-ctrl",
+    [10] = "misc-pkg-ctrl",       [11] = "energy-ctrl",
+    [12] = "doitm",               [13] = "sbdr-ssdp-no",
+    [14] = "fbsdp-no",            [15] = "psdp-no",
+    /* 16 */                      [17] = "fb-clear",
+    [18] = "fb-clear-ctrl",       [19] = "rrsba",
+    [20] = "bhi-no",              [21] = "xapic-status",
+    /* 22 */                      [23] = "ovrclk-status",
+    [24] = "pbrsb-no",
 };
 
 static const char *const str_10Ah[32] =
diff --git a/xen/include/public/arch-x86/cpufeatureset.h 
b/xen/include/public/arch-x86/cpufeatureset.h
index 032cec3ccba2..033b1a72feea 100644
--- a/xen/include/public/arch-x86/cpufeatureset.h
+++ b/xen/include/public/arch-x86/cpufeatureset.h
@@ -308,6 +308,29 @@ XEN_CPUFEATURE(AVX_NE_CONVERT,     15*32+ 5) /*A  
AVX-NE-CONVERT Instructions */
 XEN_CPUFEATURE(CET_SSS,            15*32+18) /*   CET Supervisor Shadow Stacks 
safe to use */
 
 /* Intel-defined CPU features, MSR_ARCH_CAPS 0x10a.eax, word 16 */
+XEN_CPUFEATURE(RDCL_NO,            16*32+ 0) /*A  No Rogue Data Cache Load 
(Meltdown) */
+XEN_CPUFEATURE(EIBRS,              16*32+ 1) /*A  Enhanced IBRS */
+XEN_CPUFEATURE(RSBA,               16*32+ 2) /*!A RSB Alternative (Retpoline 
not safe) */
+XEN_CPUFEATURE(SKIP_L1DFL,         16*32+ 3) /*   Don't need to flush L1D on 
VMEntry */
+XEN_CPUFEATURE(INTEL_SSB_NO,       16*32+ 4) /*A  No Speculative Store Bypass 
*/
+XEN_CPUFEATURE(MDS_NO,             16*32+ 5) /*A  No Microarchitectural Data 
Sampling */
+XEN_CPUFEATURE(IF_PSCHANGE_MC_NO,  16*32+ 6) /*A  No Instruction fetch #MC */
+XEN_CPUFEATURE(TSX_CTRL,           16*32+ 7) /*   MSR_TSX_CTRL */
+XEN_CPUFEATURE(TAA_NO,             16*32+ 8) /*A  No TSX Async Abort */
+XEN_CPUFEATURE(MCU_CTRL,           16*32+ 9) /*   MSR_MCU_CTRL */
+XEN_CPUFEATURE(MISC_PKG_CTRL,      16*32+10) /*   MSR_MISC_PKG_CTRL */
+XEN_CPUFEATURE(ENERGY_FILTERING,   16*32+11) /*   
MSR_MISC_PKG_CTRL.ENERGY_FILTERING */
+XEN_CPUFEATURE(DOITM,              16*32+12) /*   Data Operand Invariant 
Timing Mode */
+XEN_CPUFEATURE(SBDR_SSDP_NO,       16*32+13) /*A  No Shared Buffer Data Read 
or Sideband Stale Data Propagation */
+XEN_CPUFEATURE(FBSDP_NO,           16*32+14) /*A  No Fill Buffer Stale Data 
Propagation */
+XEN_CPUFEATURE(PSDP_NO,            16*32+15) /*A  No Primary Stale Data 
Propagation */
+XEN_CPUFEATURE(FB_CLEAR,           16*32+17) /*A  Fill Buffers cleared by VERW 
*/
+XEN_CPUFEATURE(FB_CLEAR_CTRL,      16*32+18) /*   
MSR_OPT_CPU_CTRL.FB_CLEAR_DIS */
+XEN_CPUFEATURE(RRSBA,              16*32+19) /*!A Restricted RSB Alternative */
+XEN_CPUFEATURE(BHI_NO,             16*32+20) /*A  No Branch History Injection  
*/
+XEN_CPUFEATURE(XAPIC_STATUS,       16*32+21) /*   MSR_XAPIC_DISABLE_STATUS */
+XEN_CPUFEATURE(OVRCLK_STATUS,      16*32+23) /*   MSR_OVERCLOCKING_STATUS */
+XEN_CPUFEATURE(PBRSB_NO,           16*32+24) /*A  No Post-Barrier RSB 
predictions */
 
 /* Intel-defined CPU features, MSR_ARCH_CAPS 0x10a.edx, word 17 */
 
diff --git a/xen/tools/gen-cpuid.py b/xen/tools/gen-cpuid.py
index 86d00bb3c273..f28ff708a2fc 100755
--- a/xen/tools/gen-cpuid.py
+++ b/xen/tools/gen-cpuid.py
@@ -325,6 +325,9 @@ def crunch_numbers(state):
 
         # In principle the TSXLDTRK insns could also be considered independent.
         RTM: [TSXLDTRK],
+
+        # The ARCH_CAPS CPUID bit enumerates the availability of the whole 
register.
+        ARCH_CAPS: list(range(RDCL_NO, RDCL_NO + 64)),
     }
 
     deep_features = tuple(sorted(deps.keys()))
-- 
2.30.2