From 64b0d9562eded654a5eed7159737d5c9b6ca266b Mon Sep 17 00:00:00 2001
From: SChernykh <sergey.v.chernykh@gmail.com>
Date: Sat, 21 Jan 2023 16:02:47 +0100
Subject: [PATCH] Fixed broken RandomX light mode mining

RandomX VMs didn't get updated properly in light mode.
---
 src/backend/cpu/CpuWorker.cpp | 6 ++++++
 src/backend/cpu/CpuWorker.h   | 1 +
 2 files changed, 7 insertions(+)

diff --git a/src/backend/cpu/CpuWorker.cpp b/src/backend/cpu/CpuWorker.cpp
index 3eb6e4683..d0047e4b7 100644
--- a/src/backend/cpu/CpuWorker.cpp
+++ b/src/backend/cpu/CpuWorker.cpp
@@ -33,6 +33,7 @@
 #include "crypto/common/Nonce.h"
 #include "crypto/common/VirtualMemory.h"
 #include "crypto/rx/Rx.h"
+#include "crypto/rx/RxCache.h"
 #include "crypto/rx/RxDataset.h"
 #include "crypto/rx/RxVm.h"
 #include "crypto/ghostrider/ghostrider.h"
@@ -145,6 +146,11 @@ void xmrig::CpuWorker<N>::allocateRandomX_VM()
         uint8_t* scratchpad = m_memory->isHugePages() ? m_memory->scratchpad() : dataset->tryAllocateScrathpad();
         m_vm = RxVm::create(dataset, scratchpad ? scratchpad : m_memory->scratchpad(), !m_hwAES, m_assembly, node());
     }
+    else if (!dataset->get() && (m_job.currentJob().seed() != m_seed)) {
+        // Update RandomX light VM with the new seed
+        randomx_vm_set_cache(m_vm, dataset->cache()->get());
+    }
+    m_seed = m_job.currentJob().seed();
 }
 #endif
 
diff --git a/src/backend/cpu/CpuWorker.h b/src/backend/cpu/CpuWorker.h
index 5fc06fd3e..18e4fed5c 100644
--- a/src/backend/cpu/CpuWorker.h
+++ b/src/backend/cpu/CpuWorker.h
@@ -97,6 +97,7 @@ private:
 
 #   ifdef XMRIG_ALGO_RANDOMX
     randomx_vm *m_vm        = nullptr;
+    Buffer m_seed;
 #   endif
 
 #   ifdef XMRIG_ALGO_GHOSTRIDER