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From: Anthony PERARD <anthony.perard@citrix.com>
To: <devel@edk2.groups.io>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Jordan Justen <jordan.l.justen@intel.com>,
	Julien Grall <julien.grall@arm.com>,
	Anthony PERARD <anthony.perard@citrix.com>,
	xen-devel@lists.xenproject.org, Laszlo Ersek <lersek@redhat.com>
Subject: [Xen-devel] [PATCH v5 06/35] OvmfPkg/XenResetVector: Add new entry point for Xen PVH
Date: Tue, 13 Aug 2019 12:30:50 +0100
Message-ID: <20190813113119.14804-7-anthony.perard@citrix.com> (raw)
In-Reply-To: <20190813113119.14804-1-anthony.perard@citrix.com>

Add a new entry point for Xen PVH that enter directly in 32bits.

Information on the expected state of the machine when this entry point
is used can be found at:
https://xenbits.xenproject.org/docs/unstable/misc/pvh.html

Also, compare to the original file [1], the two `nop' of the "resetVector"
entry point are removed. There were introduced by 8332983e2e33
("UefiCpuPkg: Replace the un-necessary WBINVD instruction at the reset
vector with two NOPs in VTF0.", 2011-08-04), but don't seems to be
useful. This is the entry point used by HVM guest (hvmloader).

[1] UefiCpuPkg/ResetVector/Vtf0/Ia16/ResetVectorVtf0.asm

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
---

Notes:
    v4:
    - remove the two nop in the HVM entry point
    
    v3:
    - rebased, SPDX
    - remove `cli' as via PVH the interrupts are guaranteed to be off
    - rewrite some comments

 .../XenResetVector/Ia16/ResetVectorVtf0.asm   | 79 +++++++++++++++++++
 OvmfPkg/XenResetVector/Ia32/XenPVHMain.asm    | 49 ++++++++++++
 OvmfPkg/XenResetVector/XenResetVector.nasmb   |  1 +
 3 files changed, 129 insertions(+)
 create mode 100644 OvmfPkg/XenResetVector/Ia16/ResetVectorVtf0.asm
 create mode 100644 OvmfPkg/XenResetVector/Ia32/XenPVHMain.asm

diff --git a/OvmfPkg/XenResetVector/Ia16/ResetVectorVtf0.asm b/OvmfPkg/XenResetVector/Ia16/ResetVectorVtf0.asm
new file mode 100644
index 0000000000..56749bdbc9
--- /dev/null
+++ b/OvmfPkg/XenResetVector/Ia16/ResetVectorVtf0.asm
@@ -0,0 +1,79 @@
+;------------------------------------------------------------------------------
+; @file
+; First code executed by processor after resetting.
+;
+; Copyright (c) 2008 - 2014, Intel Corporation. All rights reserved.<BR>
+; Copyright (c) 2019, Citrix Systems, Inc.
+;
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+BITS    16
+
+ALIGN   16
+
+;
+; Pad the image size to 4k when page tables are in VTF0
+;
+; If the VTF0 image has page tables built in, then we need to make
+; sure the end of VTF0 is 4k above where the page tables end.
+;
+; This is required so the page tables will be 4k aligned when VTF0 is
+; located just below 0x100000000 (4GB) in the firmware device.
+;
+%ifdef ALIGN_TOP_TO_4K_FOR_PAGING
+    TIMES (0x1000 - ($ - EndOfPageTables) - (fourGigabytes - xenPVHEntryPoint)) DB 0
+%endif
+
+BITS    32
+xenPVHEntryPoint:
+;
+; Entry point to use when running as a Xen PVH guest. (0xffffffd0)
+;
+; Description of the expected state of the machine when this entry point is
+; used can be found at:
+; https://xenbits.xenproject.org/docs/unstable/misc/pvh.html
+;
+    jmp     xenPVHMain
+
+BITS    16
+ALIGN   16
+
+applicationProcessorEntryPoint:
+;
+; Application Processors entry point
+;
+; GenFv generates code aligned on a 4k boundary which will jump to this
+; location.  (0xffffffe0)  This allows the Local APIC Startup IPI to be
+; used to wake up the application processors.
+;
+    jmp     EarlyApInitReal16
+
+ALIGN   8
+
+    DD      0
+
+;
+; The VTF signature
+;
+; VTF-0 means that the VTF (Volume Top File) code does not require
+; any fixups.
+;
+vtfSignature:
+    DB      'V', 'T', 'F', 0
+
+ALIGN   16
+
+resetVector:
+;
+; Reset Vector
+;
+; This is where the processor will begin execution
+;
+    jmp     EarlyBspInitReal16
+
+ALIGN   16
+
+fourGigabytes:
+
diff --git a/OvmfPkg/XenResetVector/Ia32/XenPVHMain.asm b/OvmfPkg/XenResetVector/Ia32/XenPVHMain.asm
new file mode 100644
index 0000000000..2a17fed52f
--- /dev/null
+++ b/OvmfPkg/XenResetVector/Ia32/XenPVHMain.asm
@@ -0,0 +1,49 @@
+;------------------------------------------------------------------------------
+; @file
+; An entry point use by Xen when a guest is started in PVH mode.
+;
+; Copyright (c) 2019, Citrix Systems, Inc.
+;
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+BITS    32
+
+xenPVHMain:
+    ;
+    ; 'BP' to indicate boot-strap processor
+    ;
+    mov     di, 'BP'
+
+    ;
+    ; ESP will be used as initial value of the EAX register
+    ; in Main.asm
+    ;
+    xor     esp, esp
+
+    mov     ebx, ADDR_OF(gdtr)
+    lgdt    [ebx]
+
+    mov     eax, SEC_DEFAULT_CR0
+    mov     cr0, eax
+
+    jmp     LINEAR_CODE_SEL:ADDR_OF(.jmpToNewCodeSeg)
+.jmpToNewCodeSeg:
+
+    mov     eax, SEC_DEFAULT_CR4
+    mov     cr4, eax
+
+    mov     ax, LINEAR_SEL
+    mov     ds, ax
+    mov     es, ax
+    mov     fs, ax
+    mov     gs, ax
+    mov     ss, ax
+
+    ;
+    ; Jump to the main routine of the pre-SEC code
+    ; skiping the 16-bit part of the routine and
+    ; into the 32-bit flat mode part
+    ;
+    OneTimeCallRet TransitionFromReal16To32BitFlat
diff --git a/OvmfPkg/XenResetVector/XenResetVector.nasmb b/OvmfPkg/XenResetVector/XenResetVector.nasmb
index 89a4b08bc3..0dbc4f2c1d 100644
--- a/OvmfPkg/XenResetVector/XenResetVector.nasmb
+++ b/OvmfPkg/XenResetVector/XenResetVector.nasmb
@@ -63,6 +63,7 @@
 %include "Ia16/Init16.asm"
 
 %include "Main.asm"
+%include "Ia32/XenPVHMain.asm"
 
 %include "Ia16/ResetVectorVtf0.asm"
 
-- 
Anthony PERARD

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  parent reply index

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-13 11:30 [Xen-devel] [PATCH v5 00/35] Specific platform to run OVMF in Xen PVH and HVM guests Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 01/35] OvmfPkg/ResetSystemLib: Add missing dependency on PciLib Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 02/35] OvmfPkg: Create platform OvmfXen Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 03/35] OvmfPkg: Introduce XenResetVector Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 04/35] OvmfPkg: Introduce XenPlatformPei Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 05/35] OvmfPkg/OvmfXen: Creating an ELF header Anthony PERARD
2019-08-13 11:30 ` Anthony PERARD [this message]
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 07/35] OvmfPkg/XenResetVector: Saving start of day pointer for PVH guests Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 08/35] OvmfPkg/XenResetVector: Allow jumpstart from either hvmloader or PVH Anthony PERARD
2019-08-21 16:31   ` [Xen-devel] [edk2-devel] " Laszlo Ersek
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 09/35] OvmfPkg/OvmfXen: use a TimerLib instance that depends only on the CPU Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 10/35] OvmfPkg/XenPlatformPei: Detect OVMF_INFO from hvmloader Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 11/35] OvmfPkg/XenPlatformPei: Use mXenHvmloaderInfo to get E820 Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 12/35] OvmfPkg/XenPlatformPei: Grab RSDP from PVH guest start of day struct Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 13/35] OvmfPkg/Library/XenPlatformLib: New library Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 14/35] OvmfPkg/AcpiPlatformDxe: Use XenPlatformLib Anthony PERARD
2019-08-13 11:30 ` [Xen-devel] [PATCH v5 15/35] OvmfPkg/AcpiPlatformDxe: Use Xen PVH RSDP if it exist Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 16/35] OvmfPkg/XenHypercallLib: Enable it in PEIM Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 17/35] OvmfPkg/XenPlatformPei: Reinit XenHypercallLib Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 18/35] OvmfPkg/XenPlatformPei: Introduce XenHvmloaderDetected Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 19/35] OvmfPkg/XenPlatformPei: Setup HyperPages earlier Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 20/35] OvmfPkg/XenPlatformPei: Introduce XenPvhDetected Anthony PERARD
2019-08-15  8:54   ` [Xen-devel] [edk2-devel] " Laszlo Ersek
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 21/35] OvmfPkg: Import XENMEM_memory_map hypercall to Xen/memory.h Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 22/35] OvmfPkg/XenPlatformPei: no hvmloader: get the E820 table via hypercall Anthony PERARD
2019-08-15  8:59   ` [Xen-devel] [edk2-devel] " Laszlo Ersek
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 23/35] OvmfPkg/XenPlatformPei: Rework memory detection Anthony PERARD
2019-08-15  9:26   ` [Xen-devel] [edk2-devel] " Laszlo Ersek
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 24/35] OvmfPkg/XenPlatformPei: Reserve VGA memory region, to boot Linux Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 25/35] OvmfPkg/XenPlatformPei: Ignore missing PCI Host Bridge on Xen PVH Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 26/35] OvmfPkg/XenPlatformLib: Cache result for XenDetected Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 27/35] OvmfPkg/PlatformBootManagerLib: Use XenDetected from XenPlatformLib Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 28/35] OvmfPkg/PlatformBootManagerLib: Handle the absence of PCI bus on Xen PVH Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 29/35] OvmfPkg/OvmfXen: Override PcdFSBClock to Xen vLAPIC timer frequency Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 30/35] OvmfPkg/OvmfXen: Introduce XenTimerDxe Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 31/35] OvmfPkg/PlatformBootManagerLib: Use a Xen console for ConOut/ConIn Anthony PERARD
2019-08-15  9:35   ` [Xen-devel] [edk2-devel] " Laszlo Ersek
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 32/35] OvmfPkg: Introduce PcdXenGrantFrames Anthony PERARD
2019-08-15  9:40   ` [Xen-devel] [edk2-devel] " Laszlo Ersek
2019-08-15  9:45     ` Laszlo Ersek
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 33/35] OvmfPkg: Introduce XenIoPvhDxe to initialize Grant Tables Anthony PERARD
2019-08-15  9:42   ` [Xen-devel] [edk2-devel] " Laszlo Ersek
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 34/35] OvmfPkg: Move XenRealTimeClockLib from ArmVirtPkg Anthony PERARD
2019-08-13 11:31 ` [Xen-devel] [PATCH v5 35/35] OvmfPkg/OvmfXen: use RealTimeClockRuntimeDxe from EmbeddedPkg Anthony PERARD
2019-08-15 11:03 ` [Xen-devel] [edk2-devel] [PATCH v5 00/35] Specific platform to run OVMF in Xen PVH and HVM guests Laszlo Ersek
2019-08-21 16:16   ` Laszlo Ersek

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