[PATCH v4 12/35] OvmfPkg/XenPlatformPei: Grab RSDP from PVH guest start of day struct


Anthony PERARD
 

Check if there's a start of the day struct provided to PVH guest, save
the ACPI RSDP address for later.

This patch import import arch-x86/hvm/start_info.h from xen.git.

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

Notes:
v3:
- use SPDX
- use SIGNATURE_32
- fix coding style

OvmfPkg/XenPlatformPei/XenPlatformPei.inf | 3 +
OvmfPkg/Include/Guid/XenInfo.h | 4 +
.../Xen/arch-x86/hvm/start_info.h | 143 ++++++++++++++++++
OvmfPkg/XenPlatformPei/Xen.c | 25 +++
4 files changed, 175 insertions(+)
create mode 100644 OvmfPkg/Include/IndustryStandard/Xen/arch-x86/hvm/start_info.h

diff --git a/OvmfPkg/XenPlatformPei/XenPlatformPei.inf b/OvmfPkg/XenPlatformPei/XenPlatformPei.inf
index d1265c365a..4d00206d09 100644
--- a/OvmfPkg/XenPlatformPei/XenPlatformPei.inf
+++ b/OvmfPkg/XenPlatformPei/XenPlatformPei.inf
@@ -84,6 +84,9 @@ [Pcd]
gEfiSecurityPkgTokenSpaceGuid.PcdOptionRomImageVerificationPolicy
gUefiCpuPkgTokenSpaceGuid.PcdCpuLocalApicBaseAddress

+ gUefiOvmfPkgTokenSpaceGuid.PcdXenPvhStartOfDayStructPtr
+ gUefiOvmfPkgTokenSpaceGuid.PcdXenPvhStartOfDayStructPtrSize
+
[FixedPcd]
gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress

diff --git a/OvmfPkg/Include/Guid/XenInfo.h b/OvmfPkg/Include/Guid/XenInfo.h
index b052d618fd..25743b3884 100644
--- a/OvmfPkg/Include/Guid/XenInfo.h
+++ b/OvmfPkg/Include/Guid/XenInfo.h
@@ -25,6 +25,10 @@ typedef struct {
/// Hypervisor minor version.
///
UINT16 VersionMinor;
+ ///
+ /// Pointer to the RSDP found in the hvm_start_info provided to a PVH guest
+ ///
+ VOID *RsdpPvh;
} EFI_XEN_INFO;

extern EFI_GUID gEfiXenInfoGuid;
diff --git a/OvmfPkg/Include/IndustryStandard/Xen/arch-x86/hvm/start_info.h b/OvmfPkg/Include/IndustryStandard/Xen/arch-x86/hvm/start_info.h
new file mode 100644
index 0000000000..15708d6dd5
--- /dev/null
+++ b/OvmfPkg/Include/IndustryStandard/Xen/arch-x86/hvm/start_info.h
@@ -0,0 +1,143 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright (c) 2016, Citrix Systems, Inc.
+ */
+
+#ifndef __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__
+#define __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__
+
+/*
+ * Start of day structure passed to PVH guests and to HVM guests in %ebx.
+ *
+ * NOTE: nothing will be loaded at physical address 0, so a 0 value in any
+ * of the address fields should be treated as not present.
+ *
+ * 0 +----------------+
+ * | magic | Contains the magic value XEN_HVM_START_MAGIC_VALUE
+ * | | ("xEn3" with the 0x80 bit of the "E" set).
+ * 4 +----------------+
+ * | version | Version of this structure. Current version is 1. New
+ * | | versions are guaranteed to be backwards-compatible.
+ * 8 +----------------+
+ * | flags | SIF_xxx flags.
+ * 12 +----------------+
+ * | nr_modules | Number of modules passed to the kernel.
+ * 16 +----------------+
+ * | modlist_paddr | Physical address of an array of modules
+ * | | (layout of the structure below).
+ * 24 +----------------+
+ * | cmdline_paddr | Physical address of the command line,
+ * | | a zero-terminated ASCII string.
+ * 32 +----------------+
+ * | rsdp_paddr | Physical address of the RSDP ACPI data structure.
+ * 40 +----------------+
+ * | memmap_paddr | Physical address of the (optional) memory map. Only
+ * | | present in version 1 and newer of the structure.
+ * 48 +----------------+
+ * | memmap_entries | Number of entries in the memory map table. Zero
+ * | | if there is no memory map being provided. Only
+ * | | present in version 1 and newer of the structure.
+ * 52 +----------------+
+ * | reserved | Version 1 and newer only.
+ * 56 +----------------+
+ *
+ * The layout of each entry in the module structure is the following:
+ *
+ * 0 +----------------+
+ * | paddr | Physical address of the module.
+ * 8 +----------------+
+ * | size | Size of the module in bytes.
+ * 16 +----------------+
+ * | cmdline_paddr | Physical address of the command line,
+ * | | a zero-terminated ASCII string.
+ * 24 +----------------+
+ * | reserved |
+ * 32 +----------------+
+ *
+ * The layout of each entry in the memory map table is as follows:
+ *
+ * 0 +----------------+
+ * | addr | Base address
+ * 8 +----------------+
+ * | size | Size of mapping in bytes
+ * 16 +----------------+
+ * | type | Type of mapping as defined between the hypervisor
+ * | | and guest. See XEN_HVM_MEMMAP_TYPE_* values below.
+ * 20 +----------------|
+ * | reserved |
+ * 24 +----------------+
+ *
+ * The address and sizes are always a 64bit little endian unsigned integer.
+ *
+ * NB: Xen on x86 will always try to place all the data below the 4GiB
+ * boundary.
+ *
+ * Version numbers of the hvm_start_info structure have evolved like this:
+ *
+ * Version 0: Initial implementation.
+ *
+ * Version 1: Added the memmap_paddr/memmap_entries fields (plus 4 bytes of
+ * padding) to the end of the hvm_start_info struct. These new
+ * fields can be used to pass a memory map to the guest. The
+ * memory map is optional and so guests that understand version 1
+ * of the structure must check that memmap_entries is non-zero
+ * before trying to read the memory map.
+ */
+#define XEN_HVM_START_MAGIC_VALUE 0x336ec578
+
+/*
+ * The values used in the type field of the memory map table entries are
+ * defined below and match the Address Range Types as defined in the "System
+ * Address Map Interfaces" section of the ACPI Specification. Please refer to
+ * section 15 in version 6.2 of the ACPI spec: http://uefi.org/specifications
+ */
+#define XEN_HVM_MEMMAP_TYPE_RAM 1
+#define XEN_HVM_MEMMAP_TYPE_RESERVED 2
+#define XEN_HVM_MEMMAP_TYPE_ACPI 3
+#define XEN_HVM_MEMMAP_TYPE_NVS 4
+#define XEN_HVM_MEMMAP_TYPE_UNUSABLE 5
+#define XEN_HVM_MEMMAP_TYPE_DISABLED 6
+#define XEN_HVM_MEMMAP_TYPE_PMEM 7
+
+/*
+ * C representation of the x86/HVM start info layout.
+ *
+ * The canonical definition of this layout is above, this is just a way to
+ * represent the layout described there using C types.
+ */
+struct hvm_start_info {
+ UINT32 magic; /* Contains the magic value 0x336ec578 */
+ /* ("xEn3" with the 0x80 bit of the "E" set).*/
+ UINT32 version; /* Version of this structure. */
+ UINT32 flags; /* SIF_xxx flags. */
+ UINT32 nr_modules; /* Number of modules passed to the kernel. */
+ UINT64 modlist_paddr; /* Physical address of an array of */
+ /* hvm_modlist_entry. */
+ UINT64 cmdline_paddr; /* Physical address of the command line. */
+ UINT64 rsdp_paddr; /* Physical address of the RSDP ACPI data */
+ /* structure. */
+ /* All following fields only present in version 1 and newer */
+ UINT64 memmap_paddr; /* Physical address of an array of */
+ /* hvm_memmap_table_entry. */
+ UINT32 memmap_entries; /* Number of entries in the memmap table. */
+ /* Value will be zero if there is no memory */
+ /* map being provided. */
+ UINT32 reserved; /* Must be zero. */
+};
+
+struct hvm_modlist_entry {
+ UINT64 paddr; /* Physical address of the module. */
+ UINT64 size; /* Size of the module in bytes. */
+ UINT64 cmdline_paddr; /* Physical address of the command line. */
+ UINT64 reserved;
+};
+
+struct hvm_memmap_table_entry {
+ UINT64 addr; /* Base address of the memory region */
+ UINT64 size; /* Size of the memory region in bytes */
+ UINT32 type; /* Mapping type */
+ UINT32 reserved; /* Must be zero for Version 1. */
+};
+
+#endif /* __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__ */
diff --git a/OvmfPkg/XenPlatformPei/Xen.c b/OvmfPkg/XenPlatformPei/Xen.c
index 5c7d7ddc1c..b366139a0a 100644
--- a/OvmfPkg/XenPlatformPei/Xen.c
+++ b/OvmfPkg/XenPlatformPei/Xen.c
@@ -25,6 +25,7 @@
#include <IndustryStandard/E820.h>
#include <Library/ResourcePublicationLib.h>
#include <Library/MtrrLib.h>
+#include <IndustryStandard/Xen/arch-x86/hvm/start_info.h>

#include "Platform.h"
#include "Xen.h"
@@ -86,6 +87,7 @@ XenConnect (
UINT32 XenVersion;
EFI_XEN_OVMF_INFO *Info;
CHAR8 Sig[sizeof (Info->Signature) + 1];
+ UINT32 *PVHResetVectorData;

AsmCpuid (XenLeaf + 2, &TransferPages, &TransferReg, NULL, NULL);
mXenInfo.HyperPages = AllocatePages (TransferPages);
@@ -121,6 +123,29 @@ XenConnect (
mXenHvmloaderInfo = NULL;
}

+ mXenInfo.RsdpPvh = NULL;
+
+ //
+ // Locate and use information from the start of day structure if we have
+ // booted via the PVH entry point.
+ //
+
+ PVHResetVectorData = (VOID *)(UINTN) PcdGet32 (PcdXenPvhStartOfDayStructPtr);
+ //
+ // That magic value is written in XenResetVector/Ia32/XenPVHMain.asm
+ //
+ if (PVHResetVectorData[1] == SIGNATURE_32 ('X', 'P', 'V', 'H')) {
+ struct hvm_start_info *HVMStartInfo;
+
+ HVMStartInfo = (VOID *)(UINTN) PVHResetVectorData[0];
+ if (HVMStartInfo->magic == XEN_HVM_START_MAGIC_VALUE) {
+ ASSERT (HVMStartInfo->rsdp_paddr != 0);
+ if (HVMStartInfo->rsdp_paddr != 0) {
+ mXenInfo.RsdpPvh = (VOID *)(UINTN)HVMStartInfo->rsdp_paddr;
+ }
+ }
+ }
+
BuildGuidDataHob (
&gEfiXenInfoGuid,
&mXenInfo,
--
Anthony PERARD

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