Skip to content

Commit

Permalink
x86/boot: Use memremap() to map the MPF and MPC data
Browse files Browse the repository at this point in the history 
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.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/d9464b0d7c861021ed8f494e4a40d6cd10f1eddd.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
  • Loading branch information
Tom Lendacky authored and Ingo Molnar committed Jul 18, 2017
1 parent 8f716c9 commit 5997efb
Showing 1 changed file with 70 additions and 28 deletions.
98 changes: 70 additions & 28 deletions arch/x86/kernel/mpparse.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand All @@ -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.
Expand Down Expand Up @@ -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)
Expand All @@ -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)
Expand All @@ -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
Expand All @@ -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();

Expand All @@ -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)
Expand All @@ -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) &&
Expand All @@ -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)
Expand Down Expand Up @@ -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) {
Expand All @@ -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;
}
Expand All @@ -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;
}

Expand Down

0 comments on commit 5997efb

Please sign in to comment.