diff options
| author | KarimAllah Ahmed <karahmed@amazon.de> | 2019-01-31 21:24:44 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-04-30 21:49:46 +0200 |
| commit | 0c55671f84fffe591e8435c93a8c83286fd6b8eb (patch) | |
| tree | 19ffa33fdc2f35cadd344f601b60810b3758fcd1 | |
| parent | e0bf2665ca26c1f6d6909de29bd382e7a5ee41e7 (diff) | |
kvm, x86: Properly check whether a pfn is an MMIO or not
pfn_valid check is not sufficient because it only checks if a page has a struct
page or not, if "mem=" was passed to the kernel some valid pages won't have a
struct page. This means that if guests were assigned valid memory that lies
after the mem= boundary it will be passed uncached to the guest no matter what
the guest caching attributes are for this memory.
Introduce a new function e820__mapped_raw_any which is equivalent to
e820__mapped_any but uses the original e820 unmodified and use it to
identify real *RAM*.
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/include/asm/e820/api.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/e820.c | 18 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.c | 5 |
3 files changed, 20 insertions, 4 deletions
diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h index 62be73b23d5c..e8f58ddd06d9 100644 --- a/arch/x86/include/asm/e820/api.h +++ b/arch/x86/include/asm/e820/api.h @@ -10,6 +10,7 @@ extern struct e820_table *e820_table_firmware; extern unsigned long pci_mem_start; +extern bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type); extern bool e820__mapped_any(u64 start, u64 end, enum e820_type type); extern bool e820__mapped_all(u64 start, u64 end, enum e820_type type); diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 2879e234e193..76dd605ee2a3 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -73,12 +73,13 @@ EXPORT_SYMBOL(pci_mem_start); * This function checks if any part of the range <start,end> is mapped * with type. */ -bool e820__mapped_any(u64 start, u64 end, enum e820_type type) +static bool _e820__mapped_any(struct e820_table *table, + u64 start, u64 end, enum e820_type type) { int i; - for (i = 0; i < e820_table->nr_entries; i++) { - struct e820_entry *entry = &e820_table->entries[i]; + for (i = 0; i < table->nr_entries; i++) { + struct e820_entry *entry = &table->entries[i]; if (type && entry->type != type) continue; @@ -88,6 +89,17 @@ bool e820__mapped_any(u64 start, u64 end, enum e820_type type) } return 0; } + +bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type) +{ + return _e820__mapped_any(e820_table_firmware, start, end, type); +} +EXPORT_SYMBOL_GPL(e820__mapped_raw_any); + +bool e820__mapped_any(u64 start, u64 end, enum e820_type type) +{ + return _e820__mapped_any(e820_table, start, end, type); +} EXPORT_SYMBOL_GPL(e820__mapped_any); /* diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e10962dfc203..b1f6451022e5 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -44,6 +44,7 @@ #include <asm/page.h> #include <asm/pat.h> #include <asm/cmpxchg.h> +#include <asm/e820/api.h> #include <asm/io.h> #include <asm/vmx.h> #include <asm/kvm_page_track.h> @@ -2892,7 +2893,9 @@ static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) */ (!pat_enabled() || pat_pfn_immune_to_uc_mtrr(pfn)); - return true; + return !e820__mapped_raw_any(pfn_to_hpa(pfn), + pfn_to_hpa(pfn + 1) - 1, + E820_TYPE_RAM); } /* Bits which may be returned by set_spte() */ |