diff mbox

[v10,20/38] x86, mpparse: Use memremap to map the mpf and mpc data

Message ID d9464b0d7c861021ed8f494e4a40d6cd10f1eddd.1500319216.git.thomas.lendacky@amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tom Lendacky July 17, 2017, 9:10 p.m. UTC
The SMP MP-table is built by UEFI and placed in memory in a decrypted
state. These tables are accessed using a mix of early_memremap(),
early_memunmap(), phys_to_virt() and virt_to_phys(). Change all accesses
to use early_memremap()/early_memunmap(). This allows for proper setting
of the encryption mask so that the data can be successfully accessed when
SME is active.

Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/kernel/mpparse.c | 98 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 70 insertions(+), 28 deletions(-)

Comments

Tomeu Vizoso Nov. 3, 2017, 3:12 p.m. UTC | #1
On 17 July 2017 at 23:10, Tom Lendacky <thomas.lendacky@amd.com> wrote:
> The SMP MP-table is built by UEFI and placed in memory in a decrypted
> state. These tables are accessed using a mix of early_memremap(),
> early_memunmap(), phys_to_virt() and virt_to_phys(). Change all accesses
> to use early_memremap()/early_memunmap(). This allows for proper setting
> of the encryption mask so that the data can be successfully accessed when
> SME is active.
>
> Reviewed-by: Borislav Petkov <bp@suse.de>
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
>  arch/x86/kernel/mpparse.c | 98 +++++++++++++++++++++++++++++++++--------------
>  1 file changed, 70 insertions(+), 28 deletions(-)

Hi there,

today I played a bit with crosvm [0] and noticed that 4.14-rc7 doesn't
boot. git-bisect pointed to this patch, and reverting it indeed gets
things working again.

Anybody has an idea of why this could be?

Thanks,

Tomeu

[0] https://chromium.googlesource.com/chromiumos/platform/crosvm

>
> diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
> index fd37f39..5cbb317 100644
> --- a/arch/x86/kernel/mpparse.c
> +++ b/arch/x86/kernel/mpparse.c
> @@ -429,7 +429,7 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type)
>         }
>  }
>
> -static struct mpf_intel *mpf_found;
> +static unsigned long mpf_base;
>
>  static unsigned long __init get_mpc_size(unsigned long physptr)
>  {
> @@ -451,6 +451,7 @@ static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
>
>         size = get_mpc_size(mpf->physptr);
>         mpc = early_memremap(mpf->physptr, size);
> +
>         /*
>          * Read the physical hardware table.  Anything here will
>          * override the defaults.
> @@ -497,12 +498,12 @@ static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
>   */
>  void __init default_get_smp_config(unsigned int early)
>  {
> -       struct mpf_intel *mpf = mpf_found;
> +       struct mpf_intel *mpf;
>
>         if (!smp_found_config)
>                 return;
>
> -       if (!mpf)
> +       if (!mpf_base)
>                 return;
>
>         if (acpi_lapic && early)
> @@ -515,6 +516,12 @@ void __init default_get_smp_config(unsigned int early)
>         if (acpi_lapic && acpi_ioapic)
>                 return;
>
> +       mpf = early_memremap(mpf_base, sizeof(*mpf));
> +       if (!mpf) {
> +               pr_err("MPTABLE: error mapping MP table\n");
> +               return;
> +       }
> +
>         pr_info("Intel MultiProcessor Specification v1.%d\n",
>                 mpf->specification);
>  #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
> @@ -529,7 +536,7 @@ void __init default_get_smp_config(unsigned int early)
>         /*
>          * Now see if we need to read further.
>          */
> -       if (mpf->feature1 != 0) {
> +       if (mpf->feature1) {
>                 if (early) {
>                         /*
>                          * local APIC has default address
> @@ -542,8 +549,10 @@ void __init default_get_smp_config(unsigned int early)
>                 construct_default_ISA_mptable(mpf->feature1);
>
>         } else if (mpf->physptr) {
> -               if (check_physptr(mpf, early))
> +               if (check_physptr(mpf, early)) {
> +                       early_memunmap(mpf, sizeof(*mpf));
>                         return;
> +               }
>         } else
>                 BUG();
>
> @@ -552,6 +561,8 @@ void __init default_get_smp_config(unsigned int early)
>         /*
>          * Only use the first configuration found.
>          */
> +
> +       early_memunmap(mpf, sizeof(*mpf));
>  }
>
>  static void __init smp_reserve_memory(struct mpf_intel *mpf)
> @@ -561,15 +572,16 @@ static void __init smp_reserve_memory(struct mpf_intel *mpf)
>
>  static int __init smp_scan_config(unsigned long base, unsigned long length)
>  {
> -       unsigned int *bp = phys_to_virt(base);
> +       unsigned int *bp;
>         struct mpf_intel *mpf;
> -       unsigned long mem;
> +       int ret = 0;
>
>         apic_printk(APIC_VERBOSE, "Scan for SMP in [mem %#010lx-%#010lx]\n",
>                     base, base + length - 1);
>         BUILD_BUG_ON(sizeof(*mpf) != 16);
>
>         while (length > 0) {
> +               bp = early_memremap(base, length);
>                 mpf = (struct mpf_intel *)bp;
>                 if ((*bp == SMP_MAGIC_IDENT) &&
>                     (mpf->length == 1) &&
> @@ -579,24 +591,26 @@ static int __init smp_scan_config(unsigned long base, unsigned long length)
>  #ifdef CONFIG_X86_LOCAL_APIC
>                         smp_found_config = 1;
>  #endif
> -                       mpf_found = mpf;
> +                       mpf_base = base;
>
> -                       pr_info("found SMP MP-table at [mem %#010llx-%#010llx] mapped at [%p]\n",
> -                               (unsigned long long) virt_to_phys(mpf),
> -                               (unsigned long long) virt_to_phys(mpf) +
> -                               sizeof(*mpf) - 1, mpf);
> +                       pr_info("found SMP MP-table at [mem %#010lx-%#010lx] mapped at [%p]\n",
> +                               base, base + sizeof(*mpf) - 1, mpf);
>
> -                       mem = virt_to_phys(mpf);
> -                       memblock_reserve(mem, sizeof(*mpf));
> +                       memblock_reserve(base, sizeof(*mpf));
>                         if (mpf->physptr)
>                                 smp_reserve_memory(mpf);
>
> -                       return 1;
> +                       ret = 1;
>                 }
> -               bp += 4;
> +               early_memunmap(bp, length);
> +
> +               if (ret)
> +                       break;
> +
> +               base += 16;
>                 length -= 16;
>         }
> -       return 0;
> +       return ret;
>  }
>
>  void __init default_find_smp_config(void)
> @@ -838,29 +852,40 @@ static int __init update_mp_table(void)
>         char oem[10];
>         struct mpf_intel *mpf;
>         struct mpc_table *mpc, *mpc_new;
> +       unsigned long size;
>
>         if (!enable_update_mptable)
>                 return 0;
>
> -       mpf = mpf_found;
> -       if (!mpf)
> +       if (!mpf_base)
> +               return 0;
> +
> +       mpf = early_memremap(mpf_base, sizeof(*mpf));
> +       if (!mpf) {
> +               pr_err("MPTABLE: mpf early_memremap() failed\n");
>                 return 0;
> +       }
>
>         /*
>          * Now see if we need to go further.
>          */
> -       if (mpf->feature1 != 0)
> -               return 0;
> +       if (mpf->feature1)
> +               goto do_unmap_mpf;
>
>         if (!mpf->physptr)
> -               return 0;
> +               goto do_unmap_mpf;
>
> -       mpc = phys_to_virt(mpf->physptr);
> +       size = get_mpc_size(mpf->physptr);
> +       mpc = early_memremap(mpf->physptr, size);
> +       if (!mpc) {
> +               pr_err("MPTABLE: mpc early_memremap() failed\n");
> +               goto do_unmap_mpf;
> +       }
>
>         if (!smp_check_mpc(mpc, oem, str))
> -               return 0;
> +               goto do_unmap_mpc;
>
> -       pr_info("mpf: %llx\n", (u64)virt_to_phys(mpf));
> +       pr_info("mpf: %llx\n", (u64)mpf_base);
>         pr_info("physptr: %x\n", mpf->physptr);
>
>         if (mpc_new_phys && mpc->length > mpc_new_length) {
> @@ -878,21 +903,32 @@ static int __init update_mp_table(void)
>                 new = mpf_checksum((unsigned char *)mpc, mpc->length);
>                 if (old == new) {
>                         pr_info("mpc is readonly, please try alloc_mptable instead\n");
> -                       return 0;
> +                       goto do_unmap_mpc;
>                 }
>                 pr_info("use in-position replacing\n");
>         } else {
> +               mpc_new = early_memremap(mpc_new_phys, mpc_new_length);
> +               if (!mpc_new) {
> +                       pr_err("MPTABLE: new mpc early_memremap() failed\n");
> +                       goto do_unmap_mpc;
> +               }
>                 mpf->physptr = mpc_new_phys;
> -               mpc_new = phys_to_virt(mpc_new_phys);
>                 memcpy(mpc_new, mpc, mpc->length);
> +               early_memunmap(mpc, size);
>                 mpc = mpc_new;
> +               size = mpc_new_length;
>                 /* check if we can modify that */
>                 if (mpc_new_phys - mpf->physptr) {
>                         struct mpf_intel *mpf_new;
>                         /* steal 16 bytes from [0, 1k) */
> +                       mpf_new = early_memremap(0x400 - 16, sizeof(*mpf_new));
> +                       if (!mpf_new) {
> +                               pr_err("MPTABLE: new mpf early_memremap() failed\n");
> +                               goto do_unmap_mpc;
> +                       }
>                         pr_info("mpf new: %x\n", 0x400 - 16);
> -                       mpf_new = phys_to_virt(0x400 - 16);
>                         memcpy(mpf_new, mpf, 16);
> +                       early_memunmap(mpf, sizeof(*mpf));
>                         mpf = mpf_new;
>                         mpf->physptr = mpc_new_phys;
>                 }
> @@ -909,6 +945,12 @@ static int __init update_mp_table(void)
>          */
>         replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);
>
> +do_unmap_mpc:
> +       early_memunmap(mpc, size);
> +
> +do_unmap_mpf:
> +       early_memunmap(mpf, sizeof(*mpf));
> +
>         return 0;
>  }
>
> --
> 1.9.1
>
Tom Lendacky Nov. 3, 2017, 3:31 p.m. UTC | #2
On 11/3/2017 10:12 AM, Tomeu Vizoso wrote:
> On 17 July 2017 at 23:10, Tom Lendacky <thomas.lendacky@amd.com> wrote:
>> The SMP MP-table is built by UEFI and placed in memory in a decrypted
>> state. These tables are accessed using a mix of early_memremap(),
>> early_memunmap(), phys_to_virt() and virt_to_phys(). Change all accesses
>> to use early_memremap()/early_memunmap(). This allows for proper setting
>> of the encryption mask so that the data can be successfully accessed when
>> SME is active.
>>
>> Reviewed-by: Borislav Petkov <bp@suse.de>
>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>> ---
>>   arch/x86/kernel/mpparse.c | 98 +++++++++++++++++++++++++++++++++--------------
>>   1 file changed, 70 insertions(+), 28 deletions(-)
> 
> Hi there,
> 
> today I played a bit with crosvm [0] and noticed that 4.14-rc7 doesn't
> boot. git-bisect pointed to this patch, and reverting it indeed gets
> things working again.
> 
> Anybody has an idea of why this could be?

If you send me your kernel config I'll see if I can reproduce the issue
and debug it.

Thanks,
Tom

> 
> Thanks,
> 
> Tomeu
> 
> [0] https://chromium.googlesource.com/chromiumos/platform/crosvm
> 
>>
>> diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
>> index fd37f39..5cbb317 100644
>> --- a/arch/x86/kernel/mpparse.c
>> +++ b/arch/x86/kernel/mpparse.c
>> @@ -429,7 +429,7 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type)
>>          }
>>   }
>>
>> -static struct mpf_intel *mpf_found;
>> +static unsigned long mpf_base;
>>
>>   static unsigned long __init get_mpc_size(unsigned long physptr)
>>   {
>> @@ -451,6 +451,7 @@ static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
>>
>>          size = get_mpc_size(mpf->physptr);
>>          mpc = early_memremap(mpf->physptr, size);
>> +
>>          /*
>>           * Read the physical hardware table.  Anything here will
>>           * override the defaults.
>> @@ -497,12 +498,12 @@ static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
>>    */
>>   void __init default_get_smp_config(unsigned int early)
>>   {
>> -       struct mpf_intel *mpf = mpf_found;
>> +       struct mpf_intel *mpf;
>>
>>          if (!smp_found_config)
>>                  return;
>>
>> -       if (!mpf)
>> +       if (!mpf_base)
>>                  return;
>>
>>          if (acpi_lapic && early)
>> @@ -515,6 +516,12 @@ void __init default_get_smp_config(unsigned int early)
>>          if (acpi_lapic && acpi_ioapic)
>>                  return;
>>
>> +       mpf = early_memremap(mpf_base, sizeof(*mpf));
>> +       if (!mpf) {
>> +               pr_err("MPTABLE: error mapping MP table\n");
>> +               return;
>> +       }
>> +
>>          pr_info("Intel MultiProcessor Specification v1.%d\n",
>>                  mpf->specification);
>>   #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
>> @@ -529,7 +536,7 @@ void __init default_get_smp_config(unsigned int early)
>>          /*
>>           * Now see if we need to read further.
>>           */
>> -       if (mpf->feature1 != 0) {
>> +       if (mpf->feature1) {
>>                  if (early) {
>>                          /*
>>                           * local APIC has default address
>> @@ -542,8 +549,10 @@ void __init default_get_smp_config(unsigned int early)
>>                  construct_default_ISA_mptable(mpf->feature1);
>>
>>          } else if (mpf->physptr) {
>> -               if (check_physptr(mpf, early))
>> +               if (check_physptr(mpf, early)) {
>> +                       early_memunmap(mpf, sizeof(*mpf));
>>                          return;
>> +               }
>>          } else
>>                  BUG();
>>
>> @@ -552,6 +561,8 @@ void __init default_get_smp_config(unsigned int early)
>>          /*
>>           * Only use the first configuration found.
>>           */
>> +
>> +       early_memunmap(mpf, sizeof(*mpf));
>>   }
>>
>>   static void __init smp_reserve_memory(struct mpf_intel *mpf)
>> @@ -561,15 +572,16 @@ static void __init smp_reserve_memory(struct mpf_intel *mpf)
>>
>>   static int __init smp_scan_config(unsigned long base, unsigned long length)
>>   {
>> -       unsigned int *bp = phys_to_virt(base);
>> +       unsigned int *bp;
>>          struct mpf_intel *mpf;
>> -       unsigned long mem;
>> +       int ret = 0;
>>
>>          apic_printk(APIC_VERBOSE, "Scan for SMP in [mem %#010lx-%#010lx]\n",
>>                      base, base + length - 1);
>>          BUILD_BUG_ON(sizeof(*mpf) != 16);
>>
>>          while (length > 0) {
>> +               bp = early_memremap(base, length);
>>                  mpf = (struct mpf_intel *)bp;
>>                  if ((*bp == SMP_MAGIC_IDENT) &&
>>                      (mpf->length == 1) &&
>> @@ -579,24 +591,26 @@ static int __init smp_scan_config(unsigned long base, unsigned long length)
>>   #ifdef CONFIG_X86_LOCAL_APIC
>>                          smp_found_config = 1;
>>   #endif
>> -                       mpf_found = mpf;
>> +                       mpf_base = base;
>>
>> -                       pr_info("found SMP MP-table at [mem %#010llx-%#010llx] mapped at [%p]\n",
>> -                               (unsigned long long) virt_to_phys(mpf),
>> -                               (unsigned long long) virt_to_phys(mpf) +
>> -                               sizeof(*mpf) - 1, mpf);
>> +                       pr_info("found SMP MP-table at [mem %#010lx-%#010lx] mapped at [%p]\n",
>> +                               base, base + sizeof(*mpf) - 1, mpf);
>>
>> -                       mem = virt_to_phys(mpf);
>> -                       memblock_reserve(mem, sizeof(*mpf));
>> +                       memblock_reserve(base, sizeof(*mpf));
>>                          if (mpf->physptr)
>>                                  smp_reserve_memory(mpf);
>>
>> -                       return 1;
>> +                       ret = 1;
>>                  }
>> -               bp += 4;
>> +               early_memunmap(bp, length);
>> +
>> +               if (ret)
>> +                       break;
>> +
>> +               base += 16;
>>                  length -= 16;
>>          }
>> -       return 0;
>> +       return ret;
>>   }
>>
>>   void __init default_find_smp_config(void)
>> @@ -838,29 +852,40 @@ static int __init update_mp_table(void)
>>          char oem[10];
>>          struct mpf_intel *mpf;
>>          struct mpc_table *mpc, *mpc_new;
>> +       unsigned long size;
>>
>>          if (!enable_update_mptable)
>>                  return 0;
>>
>> -       mpf = mpf_found;
>> -       if (!mpf)
>> +       if (!mpf_base)
>> +               return 0;
>> +
>> +       mpf = early_memremap(mpf_base, sizeof(*mpf));
>> +       if (!mpf) {
>> +               pr_err("MPTABLE: mpf early_memremap() failed\n");
>>                  return 0;
>> +       }
>>
>>          /*
>>           * Now see if we need to go further.
>>           */
>> -       if (mpf->feature1 != 0)
>> -               return 0;
>> +       if (mpf->feature1)
>> +               goto do_unmap_mpf;
>>
>>          if (!mpf->physptr)
>> -               return 0;
>> +               goto do_unmap_mpf;
>>
>> -       mpc = phys_to_virt(mpf->physptr);
>> +       size = get_mpc_size(mpf->physptr);
>> +       mpc = early_memremap(mpf->physptr, size);
>> +       if (!mpc) {
>> +               pr_err("MPTABLE: mpc early_memremap() failed\n");
>> +               goto do_unmap_mpf;
>> +       }
>>
>>          if (!smp_check_mpc(mpc, oem, str))
>> -               return 0;
>> +               goto do_unmap_mpc;
>>
>> -       pr_info("mpf: %llx\n", (u64)virt_to_phys(mpf));
>> +       pr_info("mpf: %llx\n", (u64)mpf_base);
>>          pr_info("physptr: %x\n", mpf->physptr);
>>
>>          if (mpc_new_phys && mpc->length > mpc_new_length) {
>> @@ -878,21 +903,32 @@ static int __init update_mp_table(void)
>>                  new = mpf_checksum((unsigned char *)mpc, mpc->length);
>>                  if (old == new) {
>>                          pr_info("mpc is readonly, please try alloc_mptable instead\n");
>> -                       return 0;
>> +                       goto do_unmap_mpc;
>>                  }
>>                  pr_info("use in-position replacing\n");
>>          } else {
>> +               mpc_new = early_memremap(mpc_new_phys, mpc_new_length);
>> +               if (!mpc_new) {
>> +                       pr_err("MPTABLE: new mpc early_memremap() failed\n");
>> +                       goto do_unmap_mpc;
>> +               }
>>                  mpf->physptr = mpc_new_phys;
>> -               mpc_new = phys_to_virt(mpc_new_phys);
>>                  memcpy(mpc_new, mpc, mpc->length);
>> +               early_memunmap(mpc, size);
>>                  mpc = mpc_new;
>> +               size = mpc_new_length;
>>                  /* check if we can modify that */
>>                  if (mpc_new_phys - mpf->physptr) {
>>                          struct mpf_intel *mpf_new;
>>                          /* steal 16 bytes from [0, 1k) */
>> +                       mpf_new = early_memremap(0x400 - 16, sizeof(*mpf_new));
>> +                       if (!mpf_new) {
>> +                               pr_err("MPTABLE: new mpf early_memremap() failed\n");
>> +                               goto do_unmap_mpc;
>> +                       }
>>                          pr_info("mpf new: %x\n", 0x400 - 16);
>> -                       mpf_new = phys_to_virt(0x400 - 16);
>>                          memcpy(mpf_new, mpf, 16);
>> +                       early_memunmap(mpf, sizeof(*mpf));
>>                          mpf = mpf_new;
>>                          mpf->physptr = mpc_new_phys;
>>                  }
>> @@ -909,6 +945,12 @@ static int __init update_mp_table(void)
>>           */
>>          replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);
>>
>> +do_unmap_mpc:
>> +       early_memunmap(mpc, size);
>> +
>> +do_unmap_mpf:
>> +       early_memunmap(mpf, sizeof(*mpf));
>> +
>>          return 0;
>>   }
>>
>> --
>> 1.9.1
>>
Tomeu Vizoso Nov. 6, 2017, 7:13 a.m. UTC | #3
On 3 November 2017 at 16:31, Tom Lendacky <thomas.lendacky@amd.com> wrote:
> On 11/3/2017 10:12 AM, Tomeu Vizoso wrote:
>>
>> On 17 July 2017 at 23:10, Tom Lendacky <thomas.lendacky@amd.com> wrote:
>>>
>>> The SMP MP-table is built by UEFI and placed in memory in a decrypted
>>> state. These tables are accessed using a mix of early_memremap(),
>>> early_memunmap(), phys_to_virt() and virt_to_phys(). Change all accesses
>>> to use early_memremap()/early_memunmap(). This allows for proper setting
>>> of the encryption mask so that the data can be successfully accessed when
>>> SME is active.
>>>
>>> Reviewed-by: Borislav Petkov <bp@suse.de>
>>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>>> ---
>>>   arch/x86/kernel/mpparse.c | 98
>>> +++++++++++++++++++++++++++++++++--------------
>>>   1 file changed, 70 insertions(+), 28 deletions(-)
>>
>>
>> Hi there,
>>
>> today I played a bit with crosvm [0] and noticed that 4.14-rc7 doesn't
>> boot. git-bisect pointed to this patch, and reverting it indeed gets
>> things working again.
>>
>> Anybody has an idea of why this could be?
>
>
> If you send me your kernel config I'll see if I can reproduce the issue
> and debug it.

x86_64_defconfig should be enough. I have pasted my dev env
instructions here in case they help:

http://blog.tomeuvizoso.net/2017/11/experiments-with-crosvm_6.html

Thanks,

Tomeu
diff mbox

Patch

diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index fd37f39..5cbb317 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -429,7 +429,7 @@  static inline void __init construct_default_ISA_mptable(int mpc_default_type)
 	}
 }
 
-static struct mpf_intel *mpf_found;
+static unsigned long mpf_base;
 
 static unsigned long __init get_mpc_size(unsigned long physptr)
 {
@@ -451,6 +451,7 @@  static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
 
 	size = get_mpc_size(mpf->physptr);
 	mpc = early_memremap(mpf->physptr, size);
+
 	/*
 	 * Read the physical hardware table.  Anything here will
 	 * override the defaults.
@@ -497,12 +498,12 @@  static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
  */
 void __init default_get_smp_config(unsigned int early)
 {
-	struct mpf_intel *mpf = mpf_found;
+	struct mpf_intel *mpf;
 
 	if (!smp_found_config)
 		return;
 
-	if (!mpf)
+	if (!mpf_base)
 		return;
 
 	if (acpi_lapic && early)
@@ -515,6 +516,12 @@  void __init default_get_smp_config(unsigned int early)
 	if (acpi_lapic && acpi_ioapic)
 		return;
 
+	mpf = early_memremap(mpf_base, sizeof(*mpf));
+	if (!mpf) {
+		pr_err("MPTABLE: error mapping MP table\n");
+		return;
+	}
+
 	pr_info("Intel MultiProcessor Specification v1.%d\n",
 		mpf->specification);
 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
@@ -529,7 +536,7 @@  void __init default_get_smp_config(unsigned int early)
 	/*
 	 * Now see if we need to read further.
 	 */
-	if (mpf->feature1 != 0) {
+	if (mpf->feature1) {
 		if (early) {
 			/*
 			 * local APIC has default address
@@ -542,8 +549,10 @@  void __init default_get_smp_config(unsigned int early)
 		construct_default_ISA_mptable(mpf->feature1);
 
 	} else if (mpf->physptr) {
-		if (check_physptr(mpf, early))
+		if (check_physptr(mpf, early)) {
+			early_memunmap(mpf, sizeof(*mpf));
 			return;
+		}
 	} else
 		BUG();
 
@@ -552,6 +561,8 @@  void __init default_get_smp_config(unsigned int early)
 	/*
 	 * Only use the first configuration found.
 	 */
+
+	early_memunmap(mpf, sizeof(*mpf));
 }
 
 static void __init smp_reserve_memory(struct mpf_intel *mpf)
@@ -561,15 +572,16 @@  static void __init smp_reserve_memory(struct mpf_intel *mpf)
 
 static int __init smp_scan_config(unsigned long base, unsigned long length)
 {
-	unsigned int *bp = phys_to_virt(base);
+	unsigned int *bp;
 	struct mpf_intel *mpf;
-	unsigned long mem;
+	int ret = 0;
 
 	apic_printk(APIC_VERBOSE, "Scan for SMP in [mem %#010lx-%#010lx]\n",
 		    base, base + length - 1);
 	BUILD_BUG_ON(sizeof(*mpf) != 16);
 
 	while (length > 0) {
+		bp = early_memremap(base, length);
 		mpf = (struct mpf_intel *)bp;
 		if ((*bp == SMP_MAGIC_IDENT) &&
 		    (mpf->length == 1) &&
@@ -579,24 +591,26 @@  static int __init smp_scan_config(unsigned long base, unsigned long length)
 #ifdef CONFIG_X86_LOCAL_APIC
 			smp_found_config = 1;
 #endif
-			mpf_found = mpf;
+			mpf_base = base;
 
-			pr_info("found SMP MP-table at [mem %#010llx-%#010llx] mapped at [%p]\n",
-				(unsigned long long) virt_to_phys(mpf),
-				(unsigned long long) virt_to_phys(mpf) +
-				sizeof(*mpf) - 1, mpf);
+			pr_info("found SMP MP-table at [mem %#010lx-%#010lx] mapped at [%p]\n",
+				base, base + sizeof(*mpf) - 1, mpf);
 
-			mem = virt_to_phys(mpf);
-			memblock_reserve(mem, sizeof(*mpf));
+			memblock_reserve(base, sizeof(*mpf));
 			if (mpf->physptr)
 				smp_reserve_memory(mpf);
 
-			return 1;
+			ret = 1;
 		}
-		bp += 4;
+		early_memunmap(bp, length);
+
+		if (ret)
+			break;
+
+		base += 16;
 		length -= 16;
 	}
-	return 0;
+	return ret;
 }
 
 void __init default_find_smp_config(void)
@@ -838,29 +852,40 @@  static int __init update_mp_table(void)
 	char oem[10];
 	struct mpf_intel *mpf;
 	struct mpc_table *mpc, *mpc_new;
+	unsigned long size;
 
 	if (!enable_update_mptable)
 		return 0;
 
-	mpf = mpf_found;
-	if (!mpf)
+	if (!mpf_base)
+		return 0;
+
+	mpf = early_memremap(mpf_base, sizeof(*mpf));
+	if (!mpf) {
+		pr_err("MPTABLE: mpf early_memremap() failed\n");
 		return 0;
+	}
 
 	/*
 	 * Now see if we need to go further.
 	 */
-	if (mpf->feature1 != 0)
-		return 0;
+	if (mpf->feature1)
+		goto do_unmap_mpf;
 
 	if (!mpf->physptr)
-		return 0;
+		goto do_unmap_mpf;
 
-	mpc = phys_to_virt(mpf->physptr);
+	size = get_mpc_size(mpf->physptr);
+	mpc = early_memremap(mpf->physptr, size);
+	if (!mpc) {
+		pr_err("MPTABLE: mpc early_memremap() failed\n");
+		goto do_unmap_mpf;
+	}
 
 	if (!smp_check_mpc(mpc, oem, str))
-		return 0;
+		goto do_unmap_mpc;
 
-	pr_info("mpf: %llx\n", (u64)virt_to_phys(mpf));
+	pr_info("mpf: %llx\n", (u64)mpf_base);
 	pr_info("physptr: %x\n", mpf->physptr);
 
 	if (mpc_new_phys && mpc->length > mpc_new_length) {
@@ -878,21 +903,32 @@  static int __init update_mp_table(void)
 		new = mpf_checksum((unsigned char *)mpc, mpc->length);
 		if (old == new) {
 			pr_info("mpc is readonly, please try alloc_mptable instead\n");
-			return 0;
+			goto do_unmap_mpc;
 		}
 		pr_info("use in-position replacing\n");
 	} else {
+		mpc_new = early_memremap(mpc_new_phys, mpc_new_length);
+		if (!mpc_new) {
+			pr_err("MPTABLE: new mpc early_memremap() failed\n");
+			goto do_unmap_mpc;
+		}
 		mpf->physptr = mpc_new_phys;
-		mpc_new = phys_to_virt(mpc_new_phys);
 		memcpy(mpc_new, mpc, mpc->length);
+		early_memunmap(mpc, size);
 		mpc = mpc_new;
+		size = mpc_new_length;
 		/* check if we can modify that */
 		if (mpc_new_phys - mpf->physptr) {
 			struct mpf_intel *mpf_new;
 			/* steal 16 bytes from [0, 1k) */
+			mpf_new = early_memremap(0x400 - 16, sizeof(*mpf_new));
+			if (!mpf_new) {
+				pr_err("MPTABLE: new mpf early_memremap() failed\n");
+				goto do_unmap_mpc;
+			}
 			pr_info("mpf new: %x\n", 0x400 - 16);
-			mpf_new = phys_to_virt(0x400 - 16);
 			memcpy(mpf_new, mpf, 16);
+			early_memunmap(mpf, sizeof(*mpf));
 			mpf = mpf_new;
 			mpf->physptr = mpc_new_phys;
 		}
@@ -909,6 +945,12 @@  static int __init update_mp_table(void)
 	 */
 	replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);
 
+do_unmap_mpc:
+	early_memunmap(mpc, size);
+
+do_unmap_mpf:
+	early_memunmap(mpf, sizeof(*mpf));
+
 	return 0;
 }