[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v4 1/8] hw/i386: Factorize PVH related functions
From: |
Stefano Garzarella |
Subject: |
Re: [PATCH v4 1/8] hw/i386: Factorize PVH related functions |
Date: |
Wed, 25 Sep 2019 10:36:04 +0200 |
User-agent: |
NeoMutt/20180716 |
Hi Sergio,
On Tue, Sep 24, 2019 at 02:44:26PM +0200, Sergio Lopez wrote:
> Extract PVH related functions from pc.c, and put them in pvh.c, so
> they can be shared with other components.
>
> Signed-off-by: Sergio Lopez <address@hidden>
> ---
> hw/i386/Makefile.objs | 1 +
> hw/i386/pc.c | 120 +++++-------------------------------------
> hw/i386/pvh.c | 113 +++++++++++++++++++++++++++++++++++++++
> hw/i386/pvh.h | 10 ++++
> 4 files changed, 136 insertions(+), 108 deletions(-)
> create mode 100644 hw/i386/pvh.c
> create mode 100644 hw/i386/pvh.h
>
> diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
> index 5d9c9efd5f..c5f20bbd72 100644
> --- a/hw/i386/Makefile.objs
> +++ b/hw/i386/Makefile.objs
> @@ -1,5 +1,6 @@
> obj-$(CONFIG_KVM) += kvm/
> obj-y += multiboot.o
> +obj-y += pvh.o
> obj-y += pc.o
> obj-$(CONFIG_I440FX) += pc_piix.o
> obj-$(CONFIG_Q35) += pc_q35.o
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index bad866fe44..10e4ced0c6 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -42,6 +42,7 @@
> #include "elf.h"
> #include "migration/vmstate.h"
> #include "multiboot.h"
> +#include "pvh.h"
> #include "hw/timer/mc146818rtc.h"
> #include "hw/dma/i8257.h"
> #include "hw/timer/i8254.h"
> @@ -116,9 +117,6 @@ static struct e820_entry *e820_table;
> static unsigned e820_entries;
> struct hpet_fw_config hpet_cfg = {.count = UINT8_MAX};
>
> -/* Physical Address of PVH entry point read from kernel ELF NOTE */
> -static size_t pvh_start_addr;
> -
> GlobalProperty pc_compat_4_1[] = {};
> const size_t pc_compat_4_1_len = G_N_ELEMENTS(pc_compat_4_1);
>
> @@ -1076,109 +1074,6 @@ struct setup_data {
> uint8_t data[0];
> } __attribute__((packed));
>
> -
> -/*
> - * The entry point into the kernel for PVH boot is different from
> - * the native entry point. The PVH entry is defined by the x86/HVM
> - * direct boot ABI and is available in an ELFNOTE in the kernel binary.
> - *
> - * This function is passed to load_elf() when it is called from
> - * load_elfboot() which then additionally checks for an ELF Note of
> - * type XEN_ELFNOTE_PHYS32_ENTRY and passes it to this function to
> - * parse the PVH entry address from the ELF Note.
> - *
> - * Due to trickery in elf_opts.h, load_elf() is actually available as
> - * load_elf32() or load_elf64() and this routine needs to be able
> - * to deal with being called as 32 or 64 bit.
> - *
> - * The address of the PVH entry point is saved to the 'pvh_start_addr'
> - * global variable. (although the entry point is 32-bit, the kernel
> - * binary can be either 32-bit or 64-bit).
> - */
> -static uint64_t read_pvh_start_addr(void *arg1, void *arg2, bool is64)
> -{
> - size_t *elf_note_data_addr;
> -
> - /* Check if ELF Note header passed in is valid */
> - if (arg1 == NULL) {
> - return 0;
> - }
> -
> - if (is64) {
> - struct elf64_note *nhdr64 = (struct elf64_note *)arg1;
> - uint64_t nhdr_size64 = sizeof(struct elf64_note);
> - uint64_t phdr_align = *(uint64_t *)arg2;
> - uint64_t nhdr_namesz = nhdr64->n_namesz;
> -
> - elf_note_data_addr =
> - ((void *)nhdr64) + nhdr_size64 +
> - QEMU_ALIGN_UP(nhdr_namesz, phdr_align);
> - } else {
> - struct elf32_note *nhdr32 = (struct elf32_note *)arg1;
> - uint32_t nhdr_size32 = sizeof(struct elf32_note);
> - uint32_t phdr_align = *(uint32_t *)arg2;
> - uint32_t nhdr_namesz = nhdr32->n_namesz;
> -
> - elf_note_data_addr =
> - ((void *)nhdr32) + nhdr_size32 +
> - QEMU_ALIGN_UP(nhdr_namesz, phdr_align);
> - }
> -
> - pvh_start_addr = *elf_note_data_addr;
> -
> - return pvh_start_addr;
> -}
> -
> -static bool load_elfboot(const char *kernel_filename,
> - int kernel_file_size,
> - uint8_t *header,
> - size_t pvh_xen_start_addr,
> - FWCfgState *fw_cfg)
> -{
> - uint32_t flags = 0;
> - uint32_t mh_load_addr = 0;
> - uint32_t elf_kernel_size = 0;
> - uint64_t elf_entry;
> - uint64_t elf_low, elf_high;
> - int kernel_size;
> -
Are we removing the following checks (ELF magic, flags) because they
are superfluous?
Should we mention this in the commit message?
> - if (ldl_p(header) != 0x464c457f) {
> - return false; /* no elfboot */
> - }
> -
> - bool elf_is64 = header[EI_CLASS] == ELFCLASS64;
> - flags = elf_is64 ?
> - ((Elf64_Ehdr *)header)->e_flags : ((Elf32_Ehdr *)header)->e_flags;
> -
> - if (flags & 0x00010004) { /* LOAD_ELF_HEADER_HAS_ADDR */
> - error_report("elfboot unsupported flags = %x", flags);
> - exit(1);
> - }
> -
> - uint64_t elf_note_type = XEN_ELFNOTE_PHYS32_ENTRY;
> - kernel_size = load_elf(kernel_filename, read_pvh_start_addr,
> - NULL, &elf_note_type, &elf_entry,
> - &elf_low, &elf_high, 0, I386_ELF_MACHINE,
> - 0, 0);
> -
> - if (kernel_size < 0) {
> - error_report("Error while loading elf kernel");
> - exit(1);
> - }
> - mh_load_addr = elf_low;
> - elf_kernel_size = elf_high - elf_low;
> -
> - if (pvh_start_addr == 0) {
> - error_report("Error loading uncompressed kernel without PVH ELF
> Note");
> - exit(1);
> - }
> - fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, pvh_start_addr);
> - fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
> - fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, elf_kernel_size);
> -
> - return true;
> -}
> -
> static void load_linux(PCMachineState *pcms,
> FWCfgState *fw_cfg)
> {
> @@ -1218,6 +1113,9 @@ static void load_linux(PCMachineState *pcms,
> if (ldl_p(header+0x202) == 0x53726448) {
> protocol = lduw_p(header+0x206);
> } else {
> + size_t pvh_start_addr;
> + uint32_t mh_load_addr = 0;
> + uint32_t elf_kernel_size = 0;
> /*
> * This could be a multiboot kernel. If it is, let's stop treating it
> * like a Linux kernel.
> @@ -1235,10 +1133,16 @@ static void load_linux(PCMachineState *pcms,
> * If load_elfboot() is successful, populate the fw_cfg info.
> */
> if (pcmc->pvh_enabled &&
> - load_elfboot(kernel_filename, kernel_size,
> - header, pvh_start_addr, fw_cfg)) {
> + pvh_load_elfboot(kernel_filename,
> + &mh_load_addr, &elf_kernel_size)) {
> fclose(f);
>
> + pvh_start_addr = pvh_get_start_addr();
> +
> + fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, pvh_start_addr);
> + fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
> + fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, elf_kernel_size);
> +
> fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
> strlen(kernel_cmdline) + 1);
> fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA, kernel_cmdline);
> diff --git a/hw/i386/pvh.c b/hw/i386/pvh.c
> new file mode 100644
> index 0000000000..1c81727811
> --- /dev/null
> +++ b/hw/i386/pvh.c
> @@ -0,0 +1,113 @@
> +/*
> + * PVH Boot Helper
> + *
> + * Copyright (C) 2019 Oracle
> + * Copyright (C) 2019 Red Hat, Inc
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qemu/units.h"
> +#include "qemu/error-report.h"
> +#include "hw/loader.h"
> +#include "cpu.h"
> +#include "elf.h"
> +#include "pvh.h"
> +
> +static size_t pvh_start_addr;
> +
> +size_t pvh_get_start_addr(void)
> +{
> + return pvh_start_addr;
> +}
> +
> +/*
> + * The entry point into the kernel for PVH boot is different from
> + * the native entry point. The PVH entry is defined by the x86/HVM
> + * direct boot ABI and is available in an ELFNOTE in the kernel binary.
> + *
> + * This function is passed to load_elf() when it is called from
> + * load_elfboot() which then additionally checks for an ELF Note of
> + * type XEN_ELFNOTE_PHYS32_ENTRY and passes it to this function to
> + * parse the PVH entry address from the ELF Note.
> + *
> + * Due to trickery in elf_opts.h, load_elf() is actually available as
> + * load_elf32() or load_elf64() and this routine needs to be able
> + * to deal with being called as 32 or 64 bit.
> + *
> + * The address of the PVH entry point is saved to the 'pvh_start_addr'
> + * global variable. (although the entry point is 32-bit, the kernel
> + * binary can be either 32-bit or 64-bit).
> + */
> +
> +static uint64_t read_pvh_start_addr(void *arg1, void *arg2, bool is64)
> +{
> + size_t *elf_note_data_addr;
> +
> + /* Check if ELF Note header passed in is valid */
> + if (arg1 == NULL) {
> + return 0;
> + }
> +
> + if (is64) {
> + struct elf64_note *nhdr64 = (struct elf64_note *)arg1;
> + uint64_t nhdr_size64 = sizeof(struct elf64_note);
> + uint64_t phdr_align = *(uint64_t *)arg2;
> + uint64_t nhdr_namesz = nhdr64->n_namesz;
> +
> + elf_note_data_addr =
> + ((void *)nhdr64) + nhdr_size64 +
> + QEMU_ALIGN_UP(nhdr_namesz, phdr_align);
> + } else {
> + struct elf32_note *nhdr32 = (struct elf32_note *)arg1;
> + uint32_t nhdr_size32 = sizeof(struct elf32_note);
> + uint32_t phdr_align = *(uint32_t *)arg2;
> + uint32_t nhdr_namesz = nhdr32->n_namesz;
> +
> + elf_note_data_addr =
> + ((void *)nhdr32) + nhdr_size32 +
> + QEMU_ALIGN_UP(nhdr_namesz, phdr_align);
> + }
> +
> + pvh_start_addr = *elf_note_data_addr;
> +
> + return pvh_start_addr;
> +}
> +
> +bool pvh_load_elfboot(const char *kernel_filename,
> + uint32_t *mh_load_addr,
> + uint32_t *elf_kernel_size)
> +{
> + uint64_t elf_entry;
> + uint64_t elf_low, elf_high;
> + int kernel_size;
> + uint64_t elf_note_type = XEN_ELFNOTE_PHYS32_ENTRY;
> +
> + kernel_size = load_elf(kernel_filename, read_pvh_start_addr,
> + NULL, &elf_note_type, &elf_entry,
> + &elf_low, &elf_high, 0, I386_ELF_MACHINE,
> + 0, 0);
> +
> + if (kernel_size < 0) {
> + error_report("Error while loading elf kernel");
> + return false;
> + }
> +
> + if (pvh_start_addr == 0) {
> + error_report("Error loading uncompressed kernel without PVH ELF
> Note");
> + return false;
> + }
> +
> + if (mh_load_addr) {
> + *mh_load_addr = elf_low;
> + }
> +
> + if (elf_kernel_size) {
> + *elf_kernel_size = elf_high - elf_low;
> + }
> +
> + return true;
> +}
> diff --git a/hw/i386/pvh.h b/hw/i386/pvh.h
> new file mode 100644
> index 0000000000..ada67ff6e8
> --- /dev/null
> +++ b/hw/i386/pvh.h
> @@ -0,0 +1,10 @@
> +#ifndef HW_I386_PVH_H
> +#define HW_I386_PVH_H
> +
> +size_t pvh_get_start_addr(void);
What about adding "size_t *pvh_start_addr" to the pvh_load_elfboot()?
Just an idea, I'm not sure if it is better...
> +
> +bool pvh_load_elfboot(const char *kernel_filename,
> + uint32_t *mh_load_addr,
> + uint32_t *elf_kernel_size);
> +
> +#endif
Thanks,
Stefano
- [PATCH v4 0/8] Introduce the microvm machine type, Sergio Lopez, 2019/09/24
- [PATCH v4 3/8] hw/virtio: Factorize virtio-mmio headers, Sergio Lopez, 2019/09/24
- [PATCH v4 2/8] hw/i386: Factorize e820 related functions, Sergio Lopez, 2019/09/24
- [PATCH v4 5/8] fw_cfg: add "modify" functions for all types, Sergio Lopez, 2019/09/24
- [PATCH v4 4/8] hw/i386: split PCMachineState deriving X86MachineState from it, Sergio Lopez, 2019/09/24