From 18238ae670fb38f5ca7002bc8da7b7aa9d612f68 Mon Sep 17 00:00:00 2001

From: Laszlo Ersek <lersek@redhat.com>

Date: Sat, 11 Jan 2014 17:59:58 +0100

Subject: [PATCH 08/22] pc_sysfw: allow flash (-pflash) memory to be used with KVM

RH-Author: Laszlo Ersek <lersek@redhat.com>

Message-id: <1389463208-6278-9-git-send-email-lersek@redhat.com>

Patchwork-id: 56621

O-Subject: [RHEL-7.0 qemu-kvm PATCH 08/18] pc_sysfw: allow flash (-pflash) memory to be used with KVM

Bugzilla: 1032346

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Amos Kong <akong@redhat.com>

RH-Acked-by: Andrew Jones <drjones@redhat.com>

From: Jordan Justen <jordan.l.justen@intel.com>

When pc-sysfw.rom_only == 0, flash memory will be

usable with kvm. In order to enable flash memory mode,

a pflash device must be created. (For example, by

using the -pflash command line parameter.)

Usage of a flash memory device with kvm requires

KVM_CAP_READONLY_MEM, and kvm will abort if

a flash device is used with an older kvm which does

not support this capability.

If a flash device is not used, then qemu/kvm will

operate in the original rom-mode.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Message-id: 1369816047-16384-5-git-send-email-jordan.l.justen@intel.com

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

(cherry picked from commit dafb82e0fc89b631d25f8def649fbfd14fec3db2)

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

---

 hw/block/pc_sysfw.c | 50 +++++++++++++++++++++++++++++++-------------------

 1 file changed, 31 insertions(+), 19 deletions(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 hw/block/pc_sysfw.c |   50 +++++++++++++++++++++++++++++++-------------------

 1 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/hw/block/pc_sysfw.c b/hw/block/pc_sysfw.c

index 4d82c70..76932fc 100644

--- a/hw/block/pc_sysfw.c

+++ b/hw/block/pc_sysfw.c

@@ -217,28 +217,40 @@ void pc_system_firmware_init(MemoryRegion *rom_memory)

     qdev_init_nofail(DEVICE(sysfw_dev));

-    if (sysfw_dev->rom_only) {

-        old_pc_system_rom_init(rom_memory, sysfw_dev->isapc_ram_fw);

-        return;

-    }

-

     pflash_drv = drive_get(IF_PFLASH, 0, 0);

-    /* Currently KVM cannot execute from device memory.

-       Use old rom based firmware initialization for KVM. */

-    /*

-     * This is a Bad Idea, because it makes enabling/disabling KVM

-     * guest-visible.  Let's fix it for real in QEMU 1.6.

-     */

-    if (kvm_enabled()) {

-        if (pflash_drv != NULL) {

-            fprintf(stderr, "qemu: pflash cannot be used with kvm enabled\n");

-            exit(1);

-        } else {

-            sysfw_dev->rom_only = 1;

-            old_pc_system_rom_init(rom_memory, sysfw_dev->isapc_ram_fw);

-            return;

+    if (pc_sysfw_flash_vs_rom_bug_compatible) {

+        /*

+         * This is a Bad Idea, because it makes enabling/disabling KVM

+         * guest-visible.  Do it only in bug-compatibility mode.

+         */

+        if (kvm_enabled()) {

+            if (pflash_drv != NULL) {

+                fprintf(stderr, "qemu: pflash cannot be used with kvm enabled\n");

+                exit(1);

+            } else {

+                /* In old pc_sysfw_flash_vs_rom_bug_compatible mode, we assume

+                 * that KVM cannot execute from device memory. In this case, we

+                 * use old rom based firmware initialization for KVM. But, since

+                 * this is different from non-kvm mode, this behavior is

+                 * undesirable */

+                sysfw_dev->rom_only = 1;

+            }

         }

+    } else if (pflash_drv == NULL) {

+        /* When a pflash drive is not found, use rom-mode */

+        sysfw_dev->rom_only = 1;

+    } else if (kvm_enabled() && !kvm_readonly_mem_enabled()) {

+        /* Older KVM cannot execute from device memory. So, flash memory

+         * cannot be used unless the readonly memory kvm capability is present. */

+        fprintf(stderr, "qemu: pflash with kvm requires KVM readonly memory support\n");

+        exit(1);

+    }

+

+    /* If rom-mode is active, use the old pc system rom initialization. */

+    if (sysfw_dev->rom_only) {

+        old_pc_system_rom_init(rom_memory, sysfw_dev->isapc_ram_fw);

+        return;

     }

     /* If a pflash drive is not found, then create one using

-- 

1.7.1