update-linux-headers: import linux/kvm_para.h header

Right now QEMU is importing arch/x86/include/uapi/asm/kvm_para.h
because it includes definitions for kvmclock and for KVM CPUID
bits.  However, other definitions for KVM hypercall values and return
codes are included in include/uapi/linux/kvm_para.h and they will be
used by SEV-SNP.

To ensure that it is possible to include both <linux/kvm_para.h> and
"standard-headers/asm-x86/kvm_para.h" without conflicts, provide
linux/kvm_para.h as a portable header too, and forward linux-headers/
files to those in include/standard-headers.  Note that <linux/kvm_para.h>
will include architecture-specific definitions as well, but
"standard-headers/linux/kvm_para.h" will not because it can be used in
architecture-independent files.

This could easily be extended to other architectures, but right now
they do not need any symbol in their specific kvm_para.h files.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/standard-headers/linux/kvm_para.h

@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __LINUX_KVM_PARA_H
+#define __LINUX_KVM_PARA_H
+
+/*
+ * This header file provides a method for making a hypercall to the host
+ * Architectures should define:
+ * - kvm_hypercall0, kvm_hypercall1...
+ * - kvm_arch_para_features
+ * - kvm_para_available
+ */
+
+/* Return values for hypercalls */
+#define KVM_ENOSYS		1000
+#define KVM_EFAULT		EFAULT
+#define KVM_EINVAL		EINVAL
+#define KVM_E2BIG		E2BIG
+#define KVM_EPERM		EPERM
+#define KVM_EOPNOTSUPP		95
+
+#define KVM_HC_VAPIC_POLL_IRQ		1
+#define KVM_HC_MMU_OP			2
+#define KVM_HC_FEATURES			3
+#define KVM_HC_PPC_MAP_MAGIC_PAGE	4
+#define KVM_HC_KICK_CPU			5
+#define KVM_HC_MIPS_GET_CLOCK_FREQ	6
+#define KVM_HC_MIPS_EXIT_VM		7
+#define KVM_HC_MIPS_CONSOLE_OUTPUT	8
+#define KVM_HC_CLOCK_PAIRING		9
+#define KVM_HC_SEND_IPI		10
+#define KVM_HC_SCHED_YIELD		11
+#define KVM_HC_MAP_GPA_RANGE		12
+
+/*
+ * hypercalls use architecture specific
+ */
+
+#endif /* __LINUX_KVM_PARA_H */

linux-headers/asm-x86/kvm_para.h

@@ -0,0 +1 @@
+#include "standard-headers/asm-x86/kvm_para.h"

linux-headers/linux/kvm_para.h

@@ -0,0 +1,2 @@
+#include "standard-headers/linux/kvm_para.h"
+#include <asm/kvm_para.h>

scripts/update-linux-headers.sh

@@ -63,6 +63,7 @@ cp_portable() {
                                      -e 'linux/kernel' \
                                      -e 'linux/sysinfo' \
                                      -e 'asm/setup_data.h' \
+                                     -e 'asm/kvm_para.h' \
                                      > /dev/null
     then
         echo "Unexpected #include in input file $f".
@@ -70,6 +71,15 @@ cp_portable() {
     fi
 
     header=$(basename "$f");
+
+    if test -z "$arch"; then
+        # Let users of include/standard-headers/linux/ headers pick the
+        # asm-* header that they care about
+        arch_cmd='/<asm\/\([^>]*\)>/d'
+    else
+        arch_cmd='s/<asm\/\([^>]*\)>/"standard-headers\/asm-'$arch'\/\1"/'
+    fi
+
     sed -e 's/__aligned_u64/__u64 __attribute__((aligned(8)))/g' \
         -e 's/__u\([0-9][0-9]*\)/uint\1_t/g' \
         -e 's/u\([0-9][0-9]*\)/uint\1_t/g' \
@@ -78,7 +88,7 @@ cp_portable() {
         -e 's/__be\([0-9][0-9]*\)/uint\1_t/g' \
         -e 's/"\(input-event-codes\.h\)"/"standard-headers\/linux\/\1"/' \
         -e 's/<linux\/\([^>]*\)>/"standard-headers\/linux\/\1"/' \
-        -e 's/<asm\/\([^>]*\)>/"standard-headers\/asm-'$arch'\/\1"/' \
+        -e "$arch_cmd" \
         -e 's/__bitwise//' \
         -e 's/__attribute__((packed))/QEMU_PACKED/' \
         -e 's/__inline__/inline/' \
@@ -158,7 +168,12 @@ EOF
         cp "$hdrdir/include/asm/unistd_32.h" "$output/linux-headers/asm-x86/"
         cp "$hdrdir/include/asm/unistd_x32.h" "$output/linux-headers/asm-x86/"
         cp "$hdrdir/include/asm/unistd_64.h" "$output/linux-headers/asm-x86/"
+
         cp_portable "$hdrdir/include/asm/kvm_para.h" "$output/include/standard-headers/asm-$arch"
+        cat <<EOF >$output/linux-headers/asm-$arch/kvm_para.h
+#include "standard-headers/asm-$arch/kvm_para.h"
+EOF
+
         # Remove everything except the macros from bootparam.h avoiding the
         # unnecessary import of several video/ist/etc headers
         sed -e '/__ASSEMBLY__/,/__ASSEMBLY__/d' \
@@ -208,6 +223,10 @@ if [ -d "$linux/LICENSES" ]; then
     done
 fi
 
+cat <<EOF >$output/linux-headers/linux/kvm_para.h
+#include "standard-headers/linux/kvm_para.h"
+#include <asm/kvm_para.h>
+EOF
 cat <<EOF >$output/linux-headers/linux/virtio_config.h
 #include "standard-headers/linux/virtio_config.h"
 EOF
@@ -230,6 +249,7 @@ for i in "$hdrdir"/include/linux/*virtio*.h \
          "$hdrdir/include/linux/ethtool.h" \
          "$hdrdir/include/linux/const.h" \
          "$hdrdir/include/linux/kernel.h" \
+         "$hdrdir/include/linux/kvm_para.h" \
          "$hdrdir/include/linux/vhost_types.h" \
          "$hdrdir/include/linux/sysinfo.h"; do
     cp_portable "$i" "$output/include/standard-headers/linux"