From: Tom Lendacky <thomas.lendacky@amd.com>
Subject: [PATCH v6 10/34] x86, x86/mm, x86/xen,
 olpc: Use __va() against just the physical address in cr3
To: linux-arch@vger.kernel.org, linux-efi@vger.kernel.org,
        kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org,
        kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        iommu@lists.linux-foundation.org
Cc: Rik van Riel <riel@redhat.com>,
        Radim =?utf-8?b?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Toshimitsu Kani <toshi.kani@hpe.com>, Arnd Bergmann <arnd@arndb.de>,
        Jonathan Corbet <corbet@lwn.net>,
        Matt Fleming <matt@codeblueprint.co.uk>,
        "Michael S. Tsirkin" <mst@redhat.com>, Joerg Roedel <joro@8bytes.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Larry Woodman <lwoodman@redhat.com>,
        Brijesh Singh <brijesh.singh@amd.com>, Ingo Molnar <mingo@redhat.com>,
        Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dave Young <dyoung@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
        Dmitry Vyukov <dvyukov@google.com>
Date: Wed, 07 Jun 2017 14:14:53 -0500
Message-ID: <20170607191453.28645.92256.stgit@tlendack-t1.amdoffice.net>
In-Reply-To: <20170607191309.28645.15241.stgit@tlendack-t1.amdoffice.net>
References: <20170607191309.28645.15241.stgit@tlendack-t1.amdoffice.net>
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The cr3 register entry can contain the SME encryption bit that indicates
the PGD is encrypted.  The encryption bit should not be used when creating
a virtual address for the PGD table.

Create a new function, read_cr3_pa(), that will extract the physical
address from the cr3 register. This function is then used where a virtual
address of the PGD needs to be created/used from the cr3 register.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/include/asm/special_insns.h |    9 +++++++++
 arch/x86/kernel/head64.c             |    2 +-
 arch/x86/mm/fault.c                  |   10 +++++-----
 arch/x86/mm/ioremap.c                |    2 +-
 arch/x86/platform/olpc/olpc-xo1-pm.c |    2 +-
 arch/x86/power/hibernate_64.c        |    2 +-
 arch/x86/xen/mmu_pv.c                |    6 +++---
 7 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 12af3e3..d8e8ace 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -234,6 +234,15 @@ static inline void clwb(volatile void *__p)
 
 #define nop() asm volatile ("nop")
 
+static inline unsigned long native_read_cr3_pa(void)
+{
+	return (native_read_cr3() & PHYSICAL_PAGE_MASK);
+}
+
+static inline unsigned long read_cr3_pa(void)
+{
+	return (read_cr3() & PHYSICAL_PAGE_MASK);
+}
 
 #endif /* __KERNEL__ */
 
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 43b7002..dc03624 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -55,7 +55,7 @@ int __init early_make_pgtable(unsigned long address)
 	pmdval_t pmd, *pmd_p;
 
 	/* Invalid address or early pgt is done ?  */
-	if (physaddr >= MAXMEM || read_cr3() != __pa_nodebug(early_level4_pgt))
+	if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_level4_pgt))
 		return -1;
 
 again:
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8ad91a0..2a1fa10c 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -346,7 +346,7 @@ static noinline int vmalloc_fault(unsigned long address)
 	 * Do _not_ use "current" here. We might be inside
 	 * an interrupt in the middle of a task switch..
 	 */
-	pgd_paddr = read_cr3();
+	pgd_paddr = read_cr3_pa();
 	pmd_k = vmalloc_sync_one(__va(pgd_paddr), address);
 	if (!pmd_k)
 		return -1;
@@ -388,7 +388,7 @@ static bool low_pfn(unsigned long pfn)
 
 static void dump_pagetable(unsigned long address)
 {
-	pgd_t *base = __va(read_cr3());
+	pgd_t *base = __va(read_cr3_pa());
 	pgd_t *pgd = &base[pgd_index(address)];
 	p4d_t *p4d;
 	pud_t *pud;
@@ -451,7 +451,7 @@ static noinline int vmalloc_fault(unsigned long address)
 	 * happen within a race in page table update. In the later
 	 * case just flush:
 	 */
-	pgd = (pgd_t *)__va(read_cr3()) + pgd_index(address);
+	pgd = (pgd_t *)__va(read_cr3_pa()) + pgd_index(address);
 	pgd_ref = pgd_offset_k(address);
 	if (pgd_none(*pgd_ref))
 		return -1;
@@ -555,7 +555,7 @@ static int bad_address(void *p)
 
 static void dump_pagetable(unsigned long address)
 {
-	pgd_t *base = __va(read_cr3() & PHYSICAL_PAGE_MASK);
+	pgd_t *base = __va(read_cr3_pa());
 	pgd_t *pgd = base + pgd_index(address);
 	p4d_t *p4d;
 	pud_t *pud;
@@ -700,7 +700,7 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
 		pgd_t *pgd;
 		pte_t *pte;
 
-		pgd = __va(read_cr3() & PHYSICAL_PAGE_MASK);
+		pgd = __va(read_cr3_pa());
 		pgd += pgd_index(address);
 
 		pte = lookup_address_in_pgd(pgd, address, &level);
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 2a0fa89..e6305dd 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -427,7 +427,7 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
 {
 	/* Don't assume we're using swapper_pg_dir at this point */
-	pgd_t *base = __va(read_cr3());
+	pgd_t *base = __va(read_cr3_pa());
 	pgd_t *pgd = &base[pgd_index(addr)];
 	p4d_t *p4d = p4d_offset(pgd, addr);
 	pud_t *pud = pud_offset(p4d, addr);
diff --git a/arch/x86/platform/olpc/olpc-xo1-pm.c b/arch/x86/platform/olpc/olpc-xo1-pm.c
index c5350fd..0668aaf 100644
--- a/arch/x86/platform/olpc/olpc-xo1-pm.c
+++ b/arch/x86/platform/olpc/olpc-xo1-pm.c
@@ -77,7 +77,7 @@ static int xo1_power_state_enter(suspend_state_t pm_state)
 
 asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
 {
-	void *pgd_addr = __va(read_cr3());
+	void *pgd_addr = __va(read_cr3_pa());
 
 	/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
 	outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index a6e21fe..0a7650d 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -150,7 +150,7 @@ static int relocate_restore_code(void)
 	memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);
 
 	/* Make the page containing the relocated code executable */
-	pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
+	pgd = (pgd_t *)__va(read_cr3_pa()) + pgd_index(relocated_restore_code);
 	p4d = p4d_offset(pgd, relocated_restore_code);
 	if (p4d_large(*p4d)) {
 		set_p4d(p4d, __p4d(p4d_val(*p4d) & ~_PAGE_NX));
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index 1f386d7..2dc5243 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2022,7 +2022,7 @@ static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr)
 	pmd_t pmd;
 	pte_t pte;
 
-	pa = read_cr3();
+	pa = read_cr3_pa();
 	pgd = native_make_pgd(xen_read_phys_ulong(pa + pgd_index(vaddr) *
 						       sizeof(pgd)));
 	if (!pgd_present(pgd))
@@ -2102,7 +2102,7 @@ void __init xen_relocate_p2m(void)
 	pt_phys = pmd_phys + PFN_PHYS(n_pmd);
 	p2m_pfn = PFN_DOWN(pt_phys) + n_pt;
 
-	pgd = __va(read_cr3());
+	pgd = __va(read_cr3_pa());
 	new_p2m = (unsigned long *)(2 * PGDIR_SIZE);
 	idx_p4d = 0;
 	save_pud = n_pud;
@@ -2209,7 +2209,7 @@ static void __init xen_write_cr3_init(unsigned long cr3)
 {
 	unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));
 
-	BUG_ON(read_cr3() != __pa(initial_page_table));
+	BUG_ON(read_cr3_pa() != __pa(initial_page_table));
 	BUG_ON(cr3 != __pa(swapper_pg_dir));
 
 	/*