6 files changed, 470 insertions, 40 deletions

diff --git a/src/core/hle/kernel/process.cpp b/src/core/hle/kernel/process.cpp
index f45ef05f6..db3ab14ce 100644
--- a/src/core/hle/kernel/process.cpp
+++ b/src/core/hle/kernel/process.cpp
@@ -129,20 +129,17 @@ u64 Process::GetTotalPhysicalMemoryAvailable() const {
     return vm_manager.GetTotalPhysicalMemoryAvailable();
 }
 
-u64 Process::GetTotalPhysicalMemoryAvailableWithoutMmHeap() const {
-    // TODO: Subtract the personal heap size from this when the
-    //       personal heap is implemented.
-    return GetTotalPhysicalMemoryAvailable();
+u64 Process::GetTotalPhysicalMemoryAvailableWithoutSystemResource() const {
+    return GetTotalPhysicalMemoryAvailable() - GetSystemResourceSize();
 }
 
 u64 Process::GetTotalPhysicalMemoryUsed() const {
-    return vm_manager.GetCurrentHeapSize() + main_thread_stack_size + code_memory_size;
+    return vm_manager.GetCurrentHeapSize() + main_thread_stack_size + code_memory_size +
+           GetSystemResourceUsage();
 }
 
-u64 Process::GetTotalPhysicalMemoryUsedWithoutMmHeap() const {
-    // TODO: Subtract the personal heap size from this when the
-    //       personal heap is implemented.
-    return GetTotalPhysicalMemoryUsed();
+u64 Process::GetTotalPhysicalMemoryUsedWithoutSystemResource() const {
+    return GetTotalPhysicalMemoryUsed() - GetSystemResourceUsage();
 }
 
 void Process::RegisterThread(const Thread* thread) {
@@ -172,6 +169,7 @@ ResultCode Process::LoadFromMetadata(const FileSys::ProgramMetadata& metadata) {
     program_id = metadata.GetTitleID();
     ideal_core = metadata.GetMainThreadCore();
     is_64bit_process = metadata.Is64BitProgram();
+    system_resource_size = metadata.GetSystemResourceSize();
 
     vm_manager.Reset(metadata.GetAddressSpaceType());
 
diff --git a/src/core/hle/kernel/process.h b/src/core/hle/kernel/process.h
index 83ea02bee..3196014da 100644
--- a/src/core/hle/kernel/process.h
+++ b/src/core/hle/kernel/process.h
@@ -168,8 +168,24 @@ public:
         return capabilities.GetPriorityMask();
     }
 
-    u32 IsVirtualMemoryEnabled() const {
-        return is_virtual_address_memory_enabled;
+    /// Gets the amount of secure memory to allocate for memory management.
+    u32 GetSystemResourceSize() const {
+        return system_resource_size;
+    }
+
+    /// Gets the amount of secure memory currently in use for memory management.
+    u32 GetSystemResourceUsage() const {
+        // On hardware, this returns the amount of system resource memory that has
+        // been used by the kernel. This is problematic for Yuzu to emulate, because
+        // system resource memory is used for page tables -- and yuzu doesn't really
+        // have a way to calculate how much memory is required for page tables for
+        // the current process at any given time.
+        // TODO: Is this even worth implementing? Games may retrieve this value via
+        // an SDK function that gets used + available system resource size for debug
+        // or diagnostic purposes. However, it seems unlikely that a game would make
+        // decisions based on how much system memory is dedicated to its page tables.
+        // Is returning a value other than zero wise?
+        return 0;
     }
 
     /// Whether this process is an AArch64 or AArch32 process.
@@ -196,15 +212,15 @@ public:
     u64 GetTotalPhysicalMemoryAvailable() const;
 
     /// Retrieves the total physical memory available to this process in bytes,
-    /// without the size of the personal heap added to it.
-    u64 GetTotalPhysicalMemoryAvailableWithoutMmHeap() const;
+    /// without the size of the personal system resource heap added to it.
+    u64 GetTotalPhysicalMemoryAvailableWithoutSystemResource() const;
 
     /// Retrieves the total physical memory used by this process in bytes.
     u64 GetTotalPhysicalMemoryUsed() const;
 
     /// Retrieves the total physical memory used by this process in bytes,
-    /// without the size of the personal heap added to it.
-    u64 GetTotalPhysicalMemoryUsedWithoutMmHeap() const;
+    /// without the size of the personal system resource heap added to it.
+    u64 GetTotalPhysicalMemoryUsedWithoutSystemResource() const;
 
     /// Gets the list of all threads created with this process as their owner.
     const std::list<const Thread*>& GetThreadList() const {
@@ -298,12 +314,16 @@ private:
     /// Title ID corresponding to the process
     u64 program_id = 0;
 
+    /// Specifies additional memory to be reserved for the process's memory management by the
+    /// system. When this is non-zero, secure memory is allocated and used for page table allocation
+    /// instead of using the normal global page tables/memory block management.
+    u32 system_resource_size = 0;
+
     /// Resource limit descriptor for this process
     SharedPtr<ResourceLimit> resource_limit;
 
     /// The ideal CPU core for this process, threads are scheduled on this core by default.
     u8 ideal_core = 0;
-    u32 is_virtual_address_memory_enabled = 0;
 
     /// The Thread Local Storage area is allocated as processes create threads,
     /// each TLS area is 0x200 bytes, so one page (0x1000) is split up in 8 parts, and each part
diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index 58374f829..a46eed3da 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -736,16 +736,16 @@ static ResultCode GetInfo(Core::System& system, u64* result, u64 info_id, u64 ha
         StackRegionBaseAddr = 14,
         StackRegionSize = 15,
         // 3.0.0+
-        IsVirtualAddressMemoryEnabled = 16,
-        PersonalMmHeapUsage = 17,
+        SystemResourceSize = 16,
+        SystemResourceUsage = 17,
         TitleId = 18,
         // 4.0.0+
         PrivilegedProcessId = 19,
         // 5.0.0+
         UserExceptionContextAddr = 20,
         // 6.0.0+
-        TotalPhysicalMemoryAvailableWithoutMmHeap = 21,
-        TotalPhysicalMemoryUsedWithoutMmHeap = 22,
+        TotalPhysicalMemoryAvailableWithoutSystemResource = 21,
+        TotalPhysicalMemoryUsedWithoutSystemResource = 22,
     };
 
     const auto info_id_type = static_cast<GetInfoType>(info_id);
@@ -763,12 +763,12 @@ static ResultCode GetInfo(Core::System& system, u64* result, u64 info_id, u64 ha
     case GetInfoType::StackRegionSize:
     case GetInfoType::TotalPhysicalMemoryAvailable:
     case GetInfoType::TotalPhysicalMemoryUsed:
-    case GetInfoType::IsVirtualAddressMemoryEnabled:
-    case GetInfoType::PersonalMmHeapUsage:
+    case GetInfoType::SystemResourceSize:
+    case GetInfoType::SystemResourceUsage:
     case GetInfoType::TitleId:
     case GetInfoType::UserExceptionContextAddr:
-    case GetInfoType::TotalPhysicalMemoryAvailableWithoutMmHeap:
-    case GetInfoType::TotalPhysicalMemoryUsedWithoutMmHeap: {
+    case GetInfoType::TotalPhysicalMemoryAvailableWithoutSystemResource:
+    case GetInfoType::TotalPhysicalMemoryUsedWithoutSystemResource: {
         if (info_sub_id != 0) {
             return ERR_INVALID_ENUM_VALUE;
         }
@@ -829,8 +829,13 @@ static ResultCode GetInfo(Core::System& system, u64* result, u64 info_id, u64 ha
             *result = process->GetTotalPhysicalMemoryUsed();
             return RESULT_SUCCESS;
 
-        case GetInfoType::IsVirtualAddressMemoryEnabled:
-            *result = process->IsVirtualMemoryEnabled();
+        case GetInfoType::SystemResourceSize:
+            *result = process->GetSystemResourceSize();
+            return RESULT_SUCCESS;
+
+        case GetInfoType::SystemResourceUsage:
+            LOG_WARNING(Kernel_SVC, "(STUBBED) Attempted to query system resource usage");
+            *result = process->GetSystemResourceUsage();
             return RESULT_SUCCESS;
 
         case GetInfoType::TitleId:
@@ -843,12 +848,12 @@ static ResultCode GetInfo(Core::System& system, u64* result, u64 info_id, u64 ha
             *result = 0;
             return RESULT_SUCCESS;
 
-        case GetInfoType::TotalPhysicalMemoryAvailableWithoutMmHeap:
-            *result = process->GetTotalPhysicalMemoryAvailable();
+        case GetInfoType::TotalPhysicalMemoryAvailableWithoutSystemResource:
+            *result = process->GetTotalPhysicalMemoryAvailableWithoutSystemResource();
             return RESULT_SUCCESS;
 
-        case GetInfoType::TotalPhysicalMemoryUsedWithoutMmHeap:
-            *result = process->GetTotalPhysicalMemoryUsedWithoutMmHeap();
+        case GetInfoType::TotalPhysicalMemoryUsedWithoutSystemResource:
+            *result = process->GetTotalPhysicalMemoryUsedWithoutSystemResource();
             return RESULT_SUCCESS;
 
         default:
@@ -953,6 +958,86 @@ static ResultCode GetInfo(Core::System& system, u64* result, u64 info_id, u64 ha
     }
 }
 
+/// Maps memory at a desired address
+static ResultCode MapPhysicalMemory(Core::System& system, VAddr addr, u64 size) {
+    LOG_DEBUG(Kernel_SVC, "called, addr=0x{:016X}, size=0x{:X}", addr, size);
+
+    if (!Common::Is4KBAligned(addr)) {
+        LOG_ERROR(Kernel_SVC, "Address is not aligned to 4KB, 0x{:016X}", addr);
+        return ERR_INVALID_ADDRESS;
+    }
+
+    if (!Common::Is4KBAligned(size)) {
+        LOG_ERROR(Kernel_SVC, "Size is not aligned to 4KB, 0x{:X}", size);
+        return ERR_INVALID_SIZE;
+    }
+
+    if (size == 0) {
+        LOG_ERROR(Kernel_SVC, "Size is zero");
+        return ERR_INVALID_SIZE;
+    }
+
+    if (!(addr < addr + size)) {
+        LOG_ERROR(Kernel_SVC, "Size causes 64-bit overflow of address");
+        return ERR_INVALID_MEMORY_RANGE;
+    }
+
+    Process* const current_process = system.Kernel().CurrentProcess();
+    auto& vm_manager = current_process->VMManager();
+
+    if (current_process->GetSystemResourceSize() == 0) {
+        LOG_ERROR(Kernel_SVC, "System Resource Size is zero");
+        return ERR_INVALID_STATE;
+    }
+
+    if (!vm_manager.IsWithinMapRegion(addr, size)) {
+        LOG_ERROR(Kernel_SVC, "Range not within map region");
+        return ERR_INVALID_MEMORY_RANGE;
+    }
+
+    return vm_manager.MapPhysicalMemory(addr, size);
+}
+
+/// Unmaps memory previously mapped via MapPhysicalMemory
+static ResultCode UnmapPhysicalMemory(Core::System& system, VAddr addr, u64 size) {
+    LOG_DEBUG(Kernel_SVC, "called, addr=0x{:016X}, size=0x{:X}", addr, size);
+
+    if (!Common::Is4KBAligned(addr)) {
+        LOG_ERROR(Kernel_SVC, "Address is not aligned to 4KB, 0x{:016X}", addr);
+        return ERR_INVALID_ADDRESS;
+    }
+
+    if (!Common::Is4KBAligned(size)) {
+        LOG_ERROR(Kernel_SVC, "Size is not aligned to 4KB, 0x{:X}", size);
+        return ERR_INVALID_SIZE;
+    }
+
+    if (size == 0) {
+        LOG_ERROR(Kernel_SVC, "Size is zero");
+        return ERR_INVALID_SIZE;
+    }
+
+    if (!(addr < addr + size)) {
+        LOG_ERROR(Kernel_SVC, "Size causes 64-bit overflow of address");
+        return ERR_INVALID_MEMORY_RANGE;
+    }
+
+    Process* const current_process = system.Kernel().CurrentProcess();
+    auto& vm_manager = current_process->VMManager();
+
+    if (current_process->GetSystemResourceSize() == 0) {
+        LOG_ERROR(Kernel_SVC, "System Resource Size is zero");
+        return ERR_INVALID_STATE;
+    }
+
+    if (!vm_manager.IsWithinMapRegion(addr, size)) {
+        LOG_ERROR(Kernel_SVC, "Range not within map region");
+        return ERR_INVALID_MEMORY_RANGE;
+    }
+
+    return vm_manager.UnmapPhysicalMemory(addr, size);
+}
+
 /// Sets the thread activity
 static ResultCode SetThreadActivity(Core::System& system, Handle handle, u32 activity) {
     LOG_DEBUG(Kernel_SVC, "called, handle=0x{:08X}, activity=0x{:08X}", handle, activity);
@@ -2310,8 +2395,8 @@ static const FunctionDef SVC_Table[] = {
     {0x29, SvcWrap<GetInfo>, "GetInfo"},
     {0x2A, nullptr, "FlushEntireDataCache"},
     {0x2B, nullptr, "FlushDataCache"},
-    {0x2C, nullptr, "MapPhysicalMemory"},
-    {0x2D, nullptr, "UnmapPhysicalMemory"},
+    {0x2C, SvcWrap<MapPhysicalMemory>, "MapPhysicalMemory"},
+    {0x2D, SvcWrap<UnmapPhysicalMemory>, "UnmapPhysicalMemory"},
     {0x2E, nullptr, "GetFutureThreadInfo"},
     {0x2F, nullptr, "GetLastThreadInfo"},
     {0x30, SvcWrap<GetResourceLimitLimitValue>, "GetResourceLimitLimitValue"},
diff --git a/src/core/hle/kernel/svc_wrap.h b/src/core/hle/kernel/svc_wrap.h
index 865473c6f..c2d8d0dc3 100644
--- a/src/core/hle/kernel/svc_wrap.h
+++ b/src/core/hle/kernel/svc_wrap.h
@@ -32,6 +32,11 @@ void SvcWrap(Core::System& system) {
     FuncReturn(system, func(system, Param(system, 0)).raw);
 }
 
+template <ResultCode func(Core::System&, u64, u64)>
+void SvcWrap(Core::System& system) {
+    FuncReturn(system, func(system, Param(system, 0), Param(system, 1)).raw);
+}
+
 template <ResultCode func(Core::System&, u32)>
 void SvcWrap(Core::System& system) {
     FuncReturn(system, func(system, static_cast<u32>(Param(system, 0))).raw);
diff --git a/src/core/hle/kernel/vm_manager.cpp b/src/core/hle/kernel/vm_manager.cpp
index 7bc925a5f..4f45fb03b 100644
--- a/src/core/hle/kernel/vm_manager.cpp
+++ b/src/core/hle/kernel/vm_manager.cpp
@@ -11,6 +11,8 @@
 #include "core/core.h"
 #include "core/file_sys/program_metadata.h"
 #include "core/hle/kernel/errors.h"
+#include "core/hle/kernel/process.h"
+#include "core/hle/kernel/resource_limit.h"
 #include "core/hle/kernel/vm_manager.h"
 #include "core/memory.h"
 #include "core/memory_setup.h"
@@ -48,10 +50,14 @@ bool VirtualMemoryArea::CanBeMergedWith(const VirtualMemoryArea& next) const {
         type != next.type) {
         return false;
     }
-    if (type == VMAType::AllocatedMemoryBlock &&
-        (backing_block != next.backing_block || offset + size != next.offset)) {
+    if ((attribute & MemoryAttribute::DeviceMapped) == MemoryAttribute::DeviceMapped) {
+        // TODO: Can device mapped memory be merged sanely?
+        // Not merging it may cause inaccuracies versus hardware when memory layout is queried.
         return false;
     }
+    if (type == VMAType::AllocatedMemoryBlock) {
+        return true;
+    }
     if (type == VMAType::BackingMemory && backing_memory + size != next.backing_memory) {
         return false;
     }
@@ -99,7 +105,7 @@ bool VMManager::IsValidHandle(VMAHandle handle) const {
 ResultVal<VMManager::VMAHandle> VMManager::MapMemoryBlock(VAddr target,
                                                           std::shared_ptr<std::vector<u8>> block,
                                                           std::size_t offset, u64 size,
-                                                          MemoryState state) {
+                                                          MemoryState state, VMAPermission perm) {
     ASSERT(block != nullptr);
     ASSERT(offset + size <= block->size());
 
@@ -109,7 +115,7 @@ ResultVal<VMManager::VMAHandle> VMManager::MapMemoryBlock(VAddr target,
     ASSERT(final_vma.size == size);
 
     final_vma.type = VMAType::AllocatedMemoryBlock;
-    final_vma.permissions = VMAPermission::ReadWrite;
+    final_vma.permissions = perm;
     final_vma.state = state;
     final_vma.backing_block = std::move(block);
     final_vma.offset = offset;
@@ -288,6 +294,166 @@ ResultVal<VAddr> VMManager::SetHeapSize(u64 size) {
     return MakeResult<VAddr>(heap_region_base);
 }
 
+ResultCode VMManager::MapPhysicalMemory(VAddr target, u64 size) {
+    const auto end_addr = target + size;
+    const auto last_addr = end_addr - 1;
+    VAddr cur_addr = target;
+
+    ResultCode result = RESULT_SUCCESS;
+
+    // Check how much memory we've already mapped.
+    const auto mapped_size_result = SizeOfAllocatedVMAsInRange(target, size);
+    if (mapped_size_result.Failed()) {
+        return mapped_size_result.Code();
+    }
+
+    // If we've already mapped the desired amount, return early.
+    const std::size_t mapped_size = *mapped_size_result;
+    if (mapped_size == size) {
+        return RESULT_SUCCESS;
+    }
+
+    // Check that we can map the memory we want.
+    const auto res_limit = system.CurrentProcess()->GetResourceLimit();
+    const u64 physmem_remaining = res_limit->GetMaxResourceValue(ResourceType::PhysicalMemory) -
+                                  res_limit->GetCurrentResourceValue(ResourceType::PhysicalMemory);
+    if (physmem_remaining < (size - mapped_size)) {
+        return ERR_RESOURCE_LIMIT_EXCEEDED;
+    }
+
+    // Keep track of the memory regions we unmap.
+    std::vector<std::pair<u64, u64>> mapped_regions;
+
+    // Iterate, trying to map memory.
+    {
+        cur_addr = target;
+
+        auto iter = FindVMA(target);
+        ASSERT_MSG(iter != vma_map.end(), "MapPhysicalMemory iter != end");
+
+        while (true) {
+            const auto& vma = iter->second;
+            const auto vma_start = vma.base;
+            const auto vma_end = vma_start + vma.size;
+            const auto vma_last = vma_end - 1;
+
+            // Map the memory block
+            const auto map_size = std::min(end_addr - cur_addr, vma_end - cur_addr);
+            if (vma.state == MemoryState::Unmapped) {
+                const auto map_res =
+                    MapMemoryBlock(cur_addr, std::make_shared<std::vector<u8>>(map_size, 0), 0,
+                                   map_size, MemoryState::Heap, VMAPermission::ReadWrite);
+                result = map_res.Code();
+                if (result.IsError()) {
+                    break;
+                }
+
+                mapped_regions.emplace_back(cur_addr, map_size);
+            }
+
+            // Break once we hit the end of the range.
+            if (last_addr <= vma_last) {
+                break;
+            }
+
+            // Advance to the next block.
+            cur_addr = vma_end;
+            iter = FindVMA(cur_addr);
+            ASSERT_MSG(iter != vma_map.end(), "MapPhysicalMemory iter != end");
+        }
+    }
+
+    // If we failed, unmap memory.
+    if (result.IsError()) {
+        for (const auto [unmap_address, unmap_size] : mapped_regions) {
+            ASSERT_MSG(UnmapRange(unmap_address, unmap_size).IsSuccess(),
+                       "MapPhysicalMemory un-map on error");
+        }
+
+        return result;
+    }
+
+    // Update amount of mapped physical memory.
+    physical_memory_mapped += size - mapped_size;
+
+    return RESULT_SUCCESS;
+}
+
+ResultCode VMManager::UnmapPhysicalMemory(VAddr target, u64 size) {
+    const auto end_addr = target + size;
+    const auto last_addr = end_addr - 1;
+    VAddr cur_addr = target;
+
+    ResultCode result = RESULT_SUCCESS;
+
+    // Check how much memory is currently mapped.
+    const auto mapped_size_result = SizeOfUnmappablePhysicalMemoryInRange(target, size);
+    if (mapped_size_result.Failed()) {
+        return mapped_size_result.Code();
+    }
+
+    // If we've already unmapped all the memory, return early.
+    const std::size_t mapped_size = *mapped_size_result;
+    if (mapped_size == 0) {
+        return RESULT_SUCCESS;
+    }
+
+    // Keep track of the memory regions we unmap.
+    std::vector<std::pair<u64, u64>> unmapped_regions;
+
+    // Try to unmap regions.
+    {
+        cur_addr = target;
+
+        auto iter = FindVMA(target);
+        ASSERT_MSG(iter != vma_map.end(), "UnmapPhysicalMemory iter != end");
+
+        while (true) {
+            const auto& vma = iter->second;
+            const auto vma_start = vma.base;
+            const auto vma_end = vma_start + vma.size;
+            const auto vma_last = vma_end - 1;
+
+            // Unmap the memory block
+            const auto unmap_size = std::min(end_addr - cur_addr, vma_end - cur_addr);
+            if (vma.state == MemoryState::Heap) {
+                result = UnmapRange(cur_addr, unmap_size);
+                if (result.IsError()) {
+                    break;
+                }
+
+                unmapped_regions.emplace_back(cur_addr, unmap_size);
+            }
+
+            // Break once we hit the end of the range.
+            if (last_addr <= vma_last) {
+                break;
+            }
+
+            // Advance to the next block.
+            cur_addr = vma_end;
+            iter = FindVMA(cur_addr);
+            ASSERT_MSG(iter != vma_map.end(), "UnmapPhysicalMemory iter != end");
+        }
+    }
+
+    // If we failed, re-map regions.
+    // TODO: Preserve memory contents?
+    if (result.IsError()) {
+        for (const auto [map_address, map_size] : unmapped_regions) {
+            const auto remap_res =
+                MapMemoryBlock(map_address, std::make_shared<std::vector<u8>>(map_size, 0), 0,
+                               map_size, MemoryState::Heap, VMAPermission::None);
+            ASSERT_MSG(remap_res.Succeeded(), "UnmapPhysicalMemory re-map on error");
+        }
+    }
+
+    // Update mapped amount
+    physical_memory_mapped -= mapped_size;
+
+    return RESULT_SUCCESS;
+}
+
 ResultCode VMManager::MapCodeMemory(VAddr dst_address, VAddr src_address, u64 size) {
     constexpr auto ignore_attribute = MemoryAttribute::LockedForIPC | MemoryAttribute::DeviceMapped;
     const auto src_check_result = CheckRangeState(
@@ -435,7 +601,7 @@ ResultCode VMManager::MirrorMemory(VAddr dst_addr, VAddr src_addr, u64 size, Mem
     // Protect mirror with permissions from old region
     Reprotect(new_vma, vma->second.permissions);
     // Remove permissions from old region
-    Reprotect(vma, VMAPermission::None);
+    ReprotectRange(src_addr, size, VMAPermission::None);
 
     return RESULT_SUCCESS;
 }
@@ -568,14 +734,14 @@ VMManager::VMAIter VMManager::SplitVMA(VMAIter vma_handle, u64 offset_in_vma) {
 VMManager::VMAIter VMManager::MergeAdjacent(VMAIter iter) {
     const VMAIter next_vma = std::next(iter);
     if (next_vma != vma_map.end() && iter->second.CanBeMergedWith(next_vma->second)) {
-        iter->second.size += next_vma->second.size;
+        MergeAdjacentVMA(iter->second, next_vma->second);
         vma_map.erase(next_vma);
     }
 
     if (iter != vma_map.begin()) {
         VMAIter prev_vma = std::prev(iter);
         if (prev_vma->second.CanBeMergedWith(iter->second)) {
-            prev_vma->second.size += iter->second.size;
+            MergeAdjacentVMA(prev_vma->second, iter->second);
             vma_map.erase(iter);
             iter = prev_vma;
         }
@@ -584,6 +750,38 @@ VMManager::VMAIter VMManager::MergeAdjacent(VMAIter iter) {
     return iter;
 }
 
+void VMManager::MergeAdjacentVMA(VirtualMemoryArea& left, const VirtualMemoryArea& right) {
+    ASSERT(left.CanBeMergedWith(right));
+
+    // Always merge allocated memory blocks, even when they don't share the same backing block.
+    if (left.type == VMAType::AllocatedMemoryBlock &&
+        (left.backing_block != right.backing_block || left.offset + left.size != right.offset)) {
+        // Check if we can save work.
+        if (left.offset == 0 && left.size == left.backing_block->size()) {
+            // Fast case: left is an entire backing block.
+            left.backing_block->insert(left.backing_block->end(),
+                                       right.backing_block->begin() + right.offset,
+                                       right.backing_block->begin() + right.offset + right.size);
+        } else {
+            // Slow case: make a new memory block for left and right.
+            auto new_memory = std::make_shared<std::vector<u8>>();
+            new_memory->insert(new_memory->end(), left.backing_block->begin() + left.offset,
+                               left.backing_block->begin() + left.offset + left.size);
+            new_memory->insert(new_memory->end(), right.backing_block->begin() + right.offset,
+                               right.backing_block->begin() + right.offset + right.size);
+            left.backing_block = new_memory;
+            left.offset = 0;
+        }
+
+        // Page table update is needed, because backing memory changed.
+        left.size += right.size;
+        UpdatePageTableForVMA(left);
+    } else {
+        // Just update the size.
+        left.size += right.size;
+    }
+}
+
 void VMManager::UpdatePageTableForVMA(const VirtualMemoryArea& vma) {
     switch (vma.type) {
     case VMAType::Free:
@@ -758,6 +956,84 @@ VMManager::CheckResults VMManager::CheckRangeState(VAddr address, u64 size, Memo
         std::make_tuple(initial_state, initial_permissions, initial_attributes & ~ignore_mask));
 }
 
+ResultVal<std::size_t> VMManager::SizeOfAllocatedVMAsInRange(VAddr address,
+                                                             std::size_t size) const {
+    const VAddr end_addr = address + size;
+    const VAddr last_addr = end_addr - 1;
+    std::size_t mapped_size = 0;
+
+    VAddr cur_addr = address;
+    auto iter = FindVMA(cur_addr);
+    ASSERT_MSG(iter != vma_map.end(), "SizeOfAllocatedVMAsInRange iter != end");
+
+    while (true) {
+        const auto& vma = iter->second;
+        const VAddr vma_start = vma.base;
+        const VAddr vma_end = vma_start + vma.size;
+        const VAddr vma_last = vma_end - 1;
+
+        // Add size if relevant.
+        if (vma.state != MemoryState::Unmapped) {
+            mapped_size += std::min(end_addr - cur_addr, vma_end - cur_addr);
+        }
+
+        // Break once we hit the end of the range.
+        if (last_addr <= vma_last) {
+            break;
+        }
+
+        // Advance to the next block.
+        cur_addr = vma_end;
+        iter = std::next(iter);
+        ASSERT_MSG(iter != vma_map.end(), "SizeOfAllocatedVMAsInRange iter != end");
+    }
+
+    return MakeResult(mapped_size);
+}
+
+ResultVal<std::size_t> VMManager::SizeOfUnmappablePhysicalMemoryInRange(VAddr address,
+                                                                        std::size_t size) const {
+    const VAddr end_addr = address + size;
+    const VAddr last_addr = end_addr - 1;
+    std::size_t mapped_size = 0;
+
+    VAddr cur_addr = address;
+    auto iter = FindVMA(cur_addr);
+    ASSERT_MSG(iter != vma_map.end(), "SizeOfUnmappablePhysicalMemoryInRange iter != end");
+
+    while (true) {
+        const auto& vma = iter->second;
+        const auto vma_start = vma.base;
+        const auto vma_end = vma_start + vma.size;
+        const auto vma_last = vma_end - 1;
+        const auto state = vma.state;
+        const auto attr = vma.attribute;
+
+        // Memory within region must be free or mapped heap.
+        if (!((state == MemoryState::Heap && attr == MemoryAttribute::None) ||
+              (state == MemoryState::Unmapped))) {
+            return ERR_INVALID_ADDRESS_STATE;
+        }
+
+        // Add size if relevant.
+        if (state != MemoryState::Unmapped) {
+            mapped_size += std::min(end_addr - cur_addr, vma_end - cur_addr);
+        }
+
+        // Break once we hit the end of the range.
+        if (last_addr <= vma_last) {
+            break;
+        }
+
+        // Advance to the next block.
+        cur_addr = vma_end;
+        iter = std::next(iter);
+        ASSERT_MSG(iter != vma_map.end(), "SizeOfUnmappablePhysicalMemoryInRange iter != end");
+    }
+
+    return MakeResult(mapped_size);
+}
+
 u64 VMManager::GetTotalPhysicalMemoryAvailable() const {
     LOG_WARNING(Kernel, "(STUBBED) called");
     return 0xF8000000;
diff --git a/src/core/hle/kernel/vm_manager.h b/src/core/hle/kernel/vm_manager.h
index 9fe6ac3f4..0aecb7499 100644
--- a/src/core/hle/kernel/vm_manager.h
+++ b/src/core/hle/kernel/vm_manager.h
@@ -349,7 +349,8 @@ public:
      * @param state MemoryState tag to attach to the VMA.
      */
     ResultVal<VMAHandle> MapMemoryBlock(VAddr target, std::shared_ptr<std::vector<u8>> block,
-                                        std::size_t offset, u64 size, MemoryState state);
+                                        std::size_t offset, u64 size, MemoryState state,
+                                        VMAPermission perm = VMAPermission::ReadWrite);
 
     /**
      * Maps an unmanaged host memory pointer at a given address.
@@ -450,6 +451,34 @@ public:
     ///
     ResultVal<VAddr> SetHeapSize(u64 size);
 
+    /// Maps memory at a given address.
+    ///
+    /// @param addr The virtual address to map memory at.
+    /// @param size The amount of memory to map.
+    ///
+    /// @note The destination address must lie within the Map region.
+    ///
+    /// @note This function requires that SystemResourceSize be non-zero,
+    ///       however, this is just because if it were not then the
+    ///       resulting page tables could be exploited on hardware by
+    ///       a malicious program. SystemResource usage does not need
+    ///       to be explicitly checked or updated here.
+    ResultCode MapPhysicalMemory(VAddr target, u64 size);
+
+    /// Unmaps memory at a given address.
+    ///
+    /// @param addr The virtual address to unmap memory at.
+    /// @param size The amount of memory to unmap.
+    ///
+    /// @note The destination address must lie within the Map region.
+    ///
+    /// @note This function requires that SystemResourceSize be non-zero,
+    ///       however, this is just because if it were not then the
+    ///       resulting page tables could be exploited on hardware by
+    ///       a malicious program. SystemResource usage does not need
+    ///       to be explicitly checked or updated here.
+    ResultCode UnmapPhysicalMemory(VAddr target, u64 size);
+
     /// Maps a region of memory as code memory.
     ///
     /// @param dst_address The base address of the region to create the aliasing memory region.
@@ -657,6 +686,11 @@ private:
      */
     VMAIter MergeAdjacent(VMAIter vma);
 
+    /**
+     * Merges two adjacent VMAs.
+     */
+    void MergeAdjacentVMA(VirtualMemoryArea& left, const VirtualMemoryArea& right);
+
     /// Updates the pages corresponding to this VMA so they match the VMA's attributes.
     void UpdatePageTableForVMA(const VirtualMemoryArea& vma);
 
@@ -701,6 +735,13 @@ private:
                                  MemoryAttribute attribute_mask, MemoryAttribute attribute,
                                  MemoryAttribute ignore_mask) const;
 
+    /// Gets the amount of memory currently mapped (state != Unmapped) in a range.
+    ResultVal<std::size_t> SizeOfAllocatedVMAsInRange(VAddr address, std::size_t size) const;
+
+    /// Gets the amount of memory unmappable by UnmapPhysicalMemory in a range.
+    ResultVal<std::size_t> SizeOfUnmappablePhysicalMemoryInRange(VAddr address,
+                                                                 std::size_t size) const;
+
     /**
      * A map covering the entirety of the managed address space, keyed by the `base` field of each
      * VMA. It must always be modified by splitting or merging VMAs, so that the invariant
@@ -742,6 +783,11 @@ private:
     // end of the range. This is essentially 'base_address + current_size'.
     VAddr heap_end = 0;
 
+    // The current amount of memory mapped via MapPhysicalMemory.
+    // This is used here (and in Nintendo's kernel) only for debugging, and does not impact
+    // any behavior.
+    u64 physical_memory_mapped = 0;
+
     Core::System& system;
 };
 } // namespace Kernel