From: Sergej Proskurin <proskurin@sec.in.tum.de>
To: xen-devel@lists.xenproject.org
Cc: Sergej Proskurin <proskurin@sec.in.tum.de>,
Julien Grall <julien.grall@arm.com>,
Stefano Stabellini <sstabellini@kernel.org>
Subject: [PATCH 7/8] arm/mem_access: Add short-descriptor based gpt
Date: Thu, 1 Jun 2017 17:19:05 +0200 [thread overview]
Message-ID: <20170601151906.10213-16-proskurin@sec.in.tum.de> (raw)
In-Reply-To: <20170601151906.10213-1-proskurin@sec.in.tum.de>
This commit adds functionality to walk the guest's page tables using the
short-descriptor translation table format for both ARMv7 and ARMv8. The
implementation is based on ARM DDI 0487A-g G4-4189 and ARM DDI 0406C-b
B3-1506.
Signed-off-by: Sergej Proskurin <proskurin@sec.in.tum.de>
---
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Julien Grall <julien.grall@arm.com>
---
xen/arch/arm/p2m.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 123 insertions(+), 2 deletions(-)
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index ea3be6f050..fa112b873c 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1558,8 +1558,129 @@ static int __p2m_walk_gpt_sd(struct p2m_domain *p2m,
vaddr_t gva, paddr_t *ipa,
unsigned int *perm_ro)
{
- /* Not implemented yet. */
- return -EFAULT;
+ int disabled = 1;
+ int32_t ttbr;
+ paddr_t mask;
+ pte_sd_t pte, *table;
+ struct page_info *page;
+ register_t ttbcr = READ_SYSREG(TCR_EL1);
+ unsigned int level = 0, n = ttbcr & TTBCR_N_MASK;
+ struct domain *d = p2m->domain;
+
+ const paddr_t offsets[2] = {
+ ((paddr_t)(gva >> 20) & ((1ULL << (12 - n)) - 1)),
+ ((paddr_t)(gva >> 12) & ((1ULL << 8) - 1))
+ };
+
+ /* TODO: Do the same (31 bit) with LPAE code!! */
+ mask = ((1ULL << REGISTER_WIDTH_32_BIT) - 1) &
+ ~((1ULL << (REGISTER_WIDTH_32_BIT - n)) - 1);
+
+ if ( n == 0 || !(gva & mask) )
+ {
+ /* Use TTBR0 for GVA to IPA translation. */
+ ttbr = READ_SYSREG64(TTBR0_EL1);
+
+ /* If TTBCR.PD0 is set, translations using TTBR0 are disabled. */
+ disabled = ( ttbcr & TTBCR_PD0 ) ? 1 : 0;
+ }
+ else
+ {
+ /* Use TTBR1 for GVA to IPA translation. */
+ ttbr = READ_SYSREG64(TTBR1_EL1);
+
+ /* If TTBCR.PD1 is set, translations using TTBR1 are disabled. */
+ disabled = ( ttbcr & TTBCR_PD1 ) ? 1 : 0;
+ }
+
+ if ( disabled )
+ return -EFAULT;
+
+ mask = (1ULL << (14 - n)) - 1;
+ page = get_page_from_gfn(d, paddr_to_pfn(ttbr & ~mask), NULL, P2M_ALLOC);
+ if ( !page )
+ return -EFAULT;
+
+ /*
+ * XXX: The 2nd level lookup table might comprise 4 concatenated 4K
+ * pages. Check how to map concatenated tables at once.
+ */
+ table = __map_domain_page(page);
+
+ /* Consider offset if n > 2. */
+ if ( n > 2 )
+ table = (pte_sd_t *)((unsigned long)table | (unsigned long)(ttbr & mask));
+
+ pte = table[offsets[level]];
+
+ unmap_domain_page(table);
+ put_page(page);
+
+ switch ( pte.walk.dt ) {
+ case 0: /* Invalid mapping. */
+ return -EFAULT;
+
+ case 1: /* Large or small page. */
+ level++;
+
+ page = get_page_from_gfn(d, (pte.walk.base >> 2), NULL, P2M_ALLOC);
+ if ( !page )
+ return -EFAULT;
+
+ table = __map_domain_page(page);
+ table = (pte_sd_t *)((unsigned long)table | ((pte.walk.base & 0x3) << 10));
+
+ pte = table[offsets[level]];
+
+ unmap_domain_page(table);
+ put_page(page);
+
+ if ( pte.walk.dt == 0 )
+ break;
+
+ if ( pte.walk.dt & 0x2 ) /* Small page. */
+ {
+ mask = (1ULL << PAGE_SHIFT_4K) - 1;
+ *ipa = (pte.bits & ~mask) | (gva & mask);
+ }
+ else /* Large page. */
+ {
+ mask = (1ULL << PAGE_SHIFT_64K) - 1;
+ *ipa = (pte.bits & ~mask) | (gva & mask);
+ }
+
+ /* Set access permissions[2:0]. */
+ *perm_ro = (pte.bits & 0x200) >> 9;
+
+ break;
+
+ case 2: /* Section. */
+ case 3: /* Section or Supersection. */
+ if ( !(pte.bits & (1ULL << 18)) ) /* Section */
+ {
+ mask = (1ULL << 20) - 1;
+ *ipa = (pte.bits & ~mask) | (gva & mask);
+ }
+ else /* Supersection */
+ {
+ mask = (1ULL << 24) - 1;
+ *ipa = (pte.bits & ~mask) | (gva & mask);
+
+ mask = ((1ULL << 24) - 1) & ~((1ULL << 20) - 1);
+ *ipa |= (pte.bits & mask) << 32;
+
+ mask = ((1ULL << 9) - 1) & ~((1ULL << 5) - 1);
+ *ipa |= (pte.bits & mask) << 36;
+ }
+
+ /* Set access permission[2]. */
+ *perm_ro = (pte.bits & 0x8000) >> 15;
+ }
+
+ if ( pte.walk.dt == 0 )
+ return -EFAULT;
+
+ return 0;
}
/*
--
2.12.2
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next prev parent reply other threads:[~2017-06-01 15:19 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-01 15:18 [RFC PATCH v2 0/8] arm/mem_access: Walk guest page tables in SW if mem_access is active Sergej Proskurin
2017-06-01 15:18 ` [RFC PATCH v2 1/8] arm/mem_access: Add (TCR_|TTBCR_)* defines Sergej Proskurin
2017-06-02 7:31 ` Julien Grall
2017-06-07 14:56 ` Sergej Proskurin
2017-06-07 15:07 ` Julien Grall
2017-06-07 15:11 ` Julien Grall
2017-06-01 15:18 ` [RFC PATCH v2 2/8] arm/mem_access: Add defines holding the width of 32/64bit regs Sergej Proskurin
2017-06-01 15:18 ` [RFC PATCH v2 3/8] arm/mem_access: Add defines supporting PTs with varying page sizes Sergej Proskurin
2017-06-02 8:27 ` Julien Grall
2017-06-01 15:18 ` [RFC PATCH v2 4/8] arm/mem_access: Add short-descriptor pte typedefs Sergej Proskurin
2017-06-02 8:50 ` Julien Grall
2017-06-01 15:18 ` [RFC PATCH v2 5/8] arm/mem_access: Add software guest-page-table walk Sergej Proskurin
2017-06-02 9:02 ` Julien Grall
2017-06-08 12:43 ` Sergej Proskurin
2017-06-09 8:19 ` Julien Grall
2017-06-01 15:18 ` [RFC PATCH v2 6/8] arm/mem_access: Add long-descriptor based gpt Sergej Proskurin
2017-06-02 12:55 ` Julien Grall
2017-06-09 11:50 ` Sergej Proskurin
2017-06-09 12:39 ` Julien Grall
2017-06-12 10:12 ` Sergej Proskurin
2017-06-12 10:44 ` Julien Grall
2017-06-12 12:31 ` Sergej Proskurin
2017-06-01 15:18 ` [RFC PATCH v2 7/8] arm/mem_access: Add short-descriptor " Sergej Proskurin
2017-06-02 15:11 ` Julien Grall
2017-06-01 15:18 ` [RFC PATCH v2 8/8] arm/mem_access: Walk the guest's pt in software Sergej Proskurin
2017-06-01 15:18 ` [PATCH 1/8] arm/mem_access: Add (TCR_|TTBCR_)* defines Sergej Proskurin
2017-06-02 15:13 ` Julien Grall
2017-06-03 8:56 ` Sergej Proskurin
2017-06-01 15:19 ` [PATCH 2/8] arm/mem_access: Add defines holding the width of 32/64bit regs Sergej Proskurin
2017-06-01 15:19 ` [PATCH 3/8] arm/mem_access: Add defines supporting PTs with varying page sizes Sergej Proskurin
2017-06-01 15:19 ` [PATCH 4/8] arm/mem_access: Add short-descriptor pte typedefs Sergej Proskurin
2017-06-01 15:19 ` [PATCH 5/8] arm/mem_access: Add software guest-page-table walk Sergej Proskurin
2017-06-01 15:19 ` [PATCH 6/8] arm/mem_access: Add long-descriptor based gpt Sergej Proskurin
2017-06-01 15:19 ` Sergej Proskurin [this message]
2017-06-01 15:19 ` [PATCH 8/8] arm/mem_access: Walk the guest's pt in software Sergej Proskurin
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