lkml.org 
[lkml]   [2017]   [Nov]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v10 20/38] x86, mpparse: Use memremap to map the mpf and mpc data
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
>

\
 
 \ /
  Last update: 2017-11-03 16:20    [W:0.202 / U:0.460 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site