From adb570cb9034f647c0be5d1161be0e8699688cfa Mon Sep 17 00:00:00 2001

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Date: Wed, 29 Mar 2017 17:22:07 +0200

Subject: [PATCH] resume: Don't attempt to use generic reboot mechanisms on

 QEMU

RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>

Message-id: <20170329172207.15471-2-dgilbert@redhat.com>

Patchwork-id: 74584

O-Subject: [RHEL-7.4 seabios PATCH 1/1] resume: Don't attempt to use generic reboot mechanisms on QEMU

Bugzilla: 1428347

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

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

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

From: Kevin O'Connor <kevin@koconnor.net>

On QEMU it's necessary to manually reset the BIOS memory region

between 0xc0000-0x100000 on a reboot.  After this manual memory reset

is completed, it's not valid to use the generic reset mechanisms.

Rename qemu_prep_reset() to qemu_reboot() and change the function to

immediately reboot after the code memcpy.

This fixes a bug that could cause code corruption on reboots - calling

the udelay() function (as invoked by i8042_reboot and/or pci_reboot)

was not valid after the BIOS was memcpy'd.

Reported-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

(cherry picked from commit c68aff57ce317d9f2d69d20eba893a10d964f316)

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

---

 src/fw/shadow.c | 14 +++++++++++++-

 src/hw/pci.c    |  1 -

 src/hw/pci.h    |  2 ++

 src/resume.c    |  4 ++--

 src/util.h      |  2 +-

 5 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/fw/shadow.c b/src/fw/shadow.c

index cd02d3a..c80b266 100644

--- a/src/fw/shadow.c

+++ b/src/fw/shadow.c

@@ -167,7 +167,7 @@ make_bios_readonly(void)

 }

 void

-qemu_prep_reset(void)

+qemu_reboot(void)

 {

     if (!CONFIG_QEMU || runningOnXen())

         return;

@@ -187,4 +187,16 @@ qemu_prep_reset(void)

     memcpy(hrp + 4, hrp + 4 + BIOS_SRC_OFFSET, cend - (hrp + 4));

     barrier();

     HaveRunPost = 0;

+    barrier();

+

+    // Request a QEMU system reset.  Do the reset in this function as

+    // the BIOS code was overwritten above and not all BIOS

+    // functionality may be available.

+

+    // Attempt PCI style reset

+    outb(0x02, PORT_PCI_REBOOT);

+    outb(0x06, PORT_PCI_REBOOT);

+

+    // Next try triple faulting the CPU to force a reset

+    asm volatile("int3");

 }

diff --git a/src/hw/pci.c b/src/hw/pci.c

index 506ee56..8e3d617 100644

--- a/src/hw/pci.c

+++ b/src/hw/pci.c

@@ -12,7 +12,6 @@

 #include "x86.h" // outl

 #define PORT_PCI_CMD           0x0cf8

-#define PORT_PCI_REBOOT        0x0cf9

 #define PORT_PCI_DATA          0x0cfc

 void pci_config_writel(u16 bdf, u32 addr, u32 val)

diff --git a/src/hw/pci.h b/src/hw/pci.h

index bf50430..ee6e196 100644

--- a/src/hw/pci.h

+++ b/src/hw/pci.h

@@ -3,6 +3,8 @@

 #include "types.h" // u32

+#define PORT_PCI_REBOOT        0x0cf9

+

 static inline u8 pci_bdf_to_bus(u16 bdf) {

     return bdf >> 8;

 }

diff --git a/src/resume.c b/src/resume.c

index 99fa34f..fb0b8a8 100644

--- a/src/resume.c

+++ b/src/resume.c

@@ -125,8 +125,8 @@ tryReboot(void)

 {

     dprintf(1, "Attempting a hard reboot\n");

-    // Setup for reset on qemu.

-    qemu_prep_reset();

+    // Use a QEMU specific reboot on QEMU

+    qemu_reboot();

     // Reboot using ACPI RESET_REG

     acpi_reboot();

diff --git a/src/util.h b/src/util.h

index 557eb8b..1dfe463 100644

--- a/src/util.h

+++ b/src/util.h

@@ -122,7 +122,7 @@ void pirtable_setup(void);

 // fw/shadow.c

 void make_bios_writable(void);

 void make_bios_readonly(void);

-void qemu_prep_reset(void);

+void qemu_reboot(void);

 // fw/smbios.c

 void smbios_legacy_setup(void);

-- 

1.8.3.1