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authorLianbo Jiang <lijiang@redhat.com>2018-09-27 10:19:51 +0300
committerBorislav Petkov <bp@suse.de>2018-10-06 12:57:51 +0300
commitc3a7a61c192ec350330128edb13db33a9bc0ace1 (patch)
tree1487bec52841498a78338aad0c6e6a70a5e9ae54 /arch/x86/mm/ioremap.c
parentb3541fbc3c25bf2ba6d03a450c07f824e318f9b9 (diff)
downloadlinux-c3a7a61c192ec350330128edb13db33a9bc0ace1.tar.xz
x86/ioremap: Add an ioremap_encrypted() helper
When SME is enabled, the memory is encrypted in the first kernel. In this case, SME also needs to be enabled in the kdump kernel, and we have to remap the old memory with the memory encryption mask. The case of concern here is if SME is active in the first kernel, and it is active too in the kdump kernel. There are four cases to be considered: a. dump vmcore It is encrypted in the first kernel, and needs be read out in the kdump kernel. b. crash notes When dumping vmcore, the people usually need to read useful information from notes, and the notes is also encrypted. c. iommu device table It's encrypted in the first kernel, kdump kernel needs to access its content to analyze and get information it needs. d. mmio of AMD iommu not encrypted in both kernels Add a new bool parameter @encrypted to __ioremap_caller(). If set, memory will be remapped with the SME mask. Add a new function ioremap_encrypted() to explicitly pass in a true value for @encrypted. Use ioremap_encrypted() for the above a, b, c cases. [ bp: cleanup commit message, extern defs in io.h and drop forgotten include. ] Signed-off-by: Lianbo Jiang <lijiang@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: kexec@lists.infradead.org Cc: tglx@linutronix.de Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: akpm@linux-foundation.org Cc: dan.j.williams@intel.com Cc: bhelgaas@google.com Cc: baiyaowei@cmss.chinamobile.com Cc: tiwai@suse.de Cc: brijesh.singh@amd.com Cc: dyoung@redhat.com Cc: bhe@redhat.com Cc: jroedel@suse.de Link: https://lkml.kernel.org/r/20180927071954.29615-2-lijiang@redhat.com
Diffstat (limited to 'arch/x86/mm/ioremap.c')
-rw-r--r--arch/x86/mm/ioremap.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index c63a545ec199..24e0920a9b25 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -131,7 +131,8 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
* caller shouldn't need to know that small detail.
*/
static void __iomem *__ioremap_caller(resource_size_t phys_addr,
- unsigned long size, enum page_cache_mode pcm, void *caller)
+ unsigned long size, enum page_cache_mode pcm,
+ void *caller, bool encrypted)
{
unsigned long offset, vaddr;
resource_size_t last_addr;
@@ -199,7 +200,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
* resulting mapping.
*/
prot = PAGE_KERNEL_IO;
- if (sev_active() && mem_flags.desc_other)
+ if ((sev_active() && mem_flags.desc_other) || encrypted)
prot = pgprot_encrypted(prot);
switch (pcm) {
@@ -291,7 +292,7 @@ void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS;
return __ioremap_caller(phys_addr, size, pcm,
- __builtin_return_address(0));
+ __builtin_return_address(0), false);
}
EXPORT_SYMBOL(ioremap_nocache);
@@ -324,7 +325,7 @@ void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size)
enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC;
return __ioremap_caller(phys_addr, size, pcm,
- __builtin_return_address(0));
+ __builtin_return_address(0), false);
}
EXPORT_SYMBOL_GPL(ioremap_uc);
@@ -341,7 +342,7 @@ EXPORT_SYMBOL_GPL(ioremap_uc);
void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
{
return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC,
- __builtin_return_address(0));
+ __builtin_return_address(0), false);
}
EXPORT_SYMBOL(ioremap_wc);
@@ -358,14 +359,21 @@ EXPORT_SYMBOL(ioremap_wc);
void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size)
{
return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT,
- __builtin_return_address(0));
+ __builtin_return_address(0), false);
}
EXPORT_SYMBOL(ioremap_wt);
+void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size)
+{
+ return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
+ __builtin_return_address(0), true);
+}
+EXPORT_SYMBOL(ioremap_encrypted);
+
void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
{
return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
- __builtin_return_address(0));
+ __builtin_return_address(0), false);
}
EXPORT_SYMBOL(ioremap_cache);
@@ -374,7 +382,7 @@ void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
{
return __ioremap_caller(phys_addr, size,
pgprot2cachemode(__pgprot(prot_val)),
- __builtin_return_address(0));
+ __builtin_return_address(0), false);
}
EXPORT_SYMBOL(ioremap_prot);