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path: root/target-s390x/mmu_helper.c
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2015-02-18s390x/mmu: Add function for accessing guest memoryThomas Huth
According to the POP specification, the parameter blocks of various functions like the IO instructions are accessed with logical addresses. Thus we need a function that can read or write a buffer from/to the guest's logical address space. This patch now provides a function that can be used to access virtual guest memory by using the mmu_translate function of QEMU to convert the virtual addresses to physical. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/kvm: Add function for injecting pgm access exceptionsThomas Huth
Program access exceptions are defined to deliver a translation exception code in the low-core. Add a function trigger_access_exception() that generates the proper program interrupt on both KVM and non-KVM systems and switch the existing code to use it. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Clean up mmu_translate_asc()Thomas Huth
We can get rid of the switch(asc) in mmu_translate_asc() by simply selecting the right control register ASCE in the mmu_translate() function already. This patch is based on an original patch/idea by Ralf Hoppe. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Check bit 52 in page table entryThomas Huth
Bit 52 in a page table entry has always to be zero, or a translation specification exception is to be recognized. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Renaming related to the ASCE confusionThomas Huth
An Address Space Control Element (ASCE) is only the very first unit of an s390 address translation (normally residing in one of the control registers). The entries in the page tables are called differently. So let's call the relevant variable pt_entry instead of asce in mmu_translate_pte() to avoid future confusion (thus there is no functional change in this patch, just renaming). Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Add support for read-only regionsThomas Huth
If the "DAT-protection" bit is set in the region table entry and EDAT is enabled, only read accesses are allowed in the corresponding memory area. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Fix the exception codes for illegal table entriesThomas Huth
Each different level of region/segment table has a dedicated exception type for illegal entries. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Fix exception types when checking the ASCEsThomas Huth
If an ASCE has illegal bits set, an ASCE-type exception should be generated instead of a translation specification exception. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Fix translation exception code in lowcoreThomas Huth
The address space bits in the translation exception code were wrong. In fact, we can simply copy the bits from the PSW, so there's no need for the trans_bits() function anymore. Additionally, we now also set the fetch/store bits in the translation exception code, so a guest can determine whether the exception occured during a write or during a read. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Skip exceptions properly when translating addresses for debugThomas Huth
When a fault occurs during the MMU lookup in s390_cpu_get_phys_page_debug(), the trigger_page_fault() function writes the translation exception code into the lowcore - something you would not expect during a memory access by the debugger. Ease this problem by adding an additional parameter to mmu_translate() which can be used to specify whether a program check and the translation exception code should be injected or not. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Check table length and offset fieldsThomas Huth
The ACSEs have a table length field and the region entries have table length and offset fields which must be checked during translation to see whether the given virtual address is really covered by the translation table. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Fix the handling of the table levelsThomas Huth
The current code used a wrong and very confusing way of dealing with the table levels by introducing a "fake level above current". However, the real problem was simply that the checks for the region/segment invalid bit and for the matching region/segment level was done at the wrong spot in the code - it has to be done after the first table entry has been looked up instead (e.g. there is also no "invalid" bit in the ASCE itself and the current "level" has to be the same as the level in the entry that we just looked up). Also the entries for the segment table are quite a bit different compared to the region table entries. So this patch moves the related code into the function mmu_translate_segment() to make it clear at which table level we currently are and to get rid of the ugly switch-statement in the function mmu_translate_region(). Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Fix the check for the real-space designation bitThomas Huth
The real-space designation bits live in the ASCEs, not in the table entries, so the check must be done before we start walking the MMU table. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-02-18s390x/mmu: Move mmu_translate() and friends to separate fileThomas Huth
helper.c is quite overcrowded already, so let's move the MMU translation to a separate file instead (like it has been done with the other targets already). Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>