diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 079f9c7979e..6b7b6e4b359 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -211,7 +211,7 @@ arm_test:
 
 .windows-docker-vs2019:
   variables:
-    WINDOWS_TAG: "2020-03-24"
+    WINDOWS_TAG: "2020-05-05-llvm"
     WINDOWS_IMAGE: "$CI_REGISTRY_IMAGE/windows/x64_build:$WINDOWS_TAG"
     WINDOWS_UPSTREAM_IMAGE: "$CI_REGISTRY/$FDO_UPSTREAM_REPO/windows/x64_build:$WINDOWS_TAG"
 
@@ -222,6 +222,7 @@ windows_build_vs2019:
   stage: container
   variables:
     GIT_STRATEGY: fetch # we do actually need the full repository though
+  timeout: 4h # LLVM takes ages
   tags:
     - windows
     - shell
diff --git a/.gitlab-ci/windows/mesa_build.ps1 b/.gitlab-ci/windows/mesa_build.ps1
index 8d7b79c6497..5c57c29bad9 100644
--- a/.gitlab-ci/windows/mesa_build.ps1
+++ b/.gitlab-ci/windows/mesa_build.ps1
@@ -6,7 +6,7 @@ Get-Date
 Write-Host "Compiling Mesa"
 $builddir = New-Item -ItemType Directory -Name "build"
 Push-Location $builddir.FullName
-cmd.exe /C "C:\BuildTools\Common7\Tools\VsDevCmd.bat -host_arch=amd64 -arch=amd64 && meson -Dgallium-drivers=swrast -Dbuild-tests=true .. && ninja test"
+cmd.exe /C 'C:\BuildTools\Common7\Tools\VsDevCmd.bat -host_arch=amd64 -arch=amd64 && meson --default-library=static --buildtype=release -Db_vscrt=mt --cmake-prefix-path="C:\llvm-10" --pkg-config-path="C:\llvm-10\lib\pkgconfig;C:\llvm-10\share\pkgconfig;C:\spirv-tools\lib\pkgconfig" -Dllvm=true -Dshared-llvm=false -Dgallium-drivers=swrast -Dbuild-tests=true && ninja test'
 $buildstatus = $?
 Pop-Location
 Remove-Item -Recurse -Path $builddir
diff --git a/.gitlab-ci/windows/mesa_deps.ps1 b/.gitlab-ci/windows/mesa_deps.ps1
index 28499e484ce..7fa52ad0053 100644
--- a/.gitlab-ci/windows/mesa_deps.ps1
+++ b/.gitlab-ci/windows/mesa_deps.ps1
@@ -10,7 +10,7 @@ Write-Host "Installing Chocolatey packages"
 For ($i = 0; $i -lt 5; $i++) {
   choco install -y python3 --params="/InstallDir:C:\python3"
   $python_install = $?
-  choco install --allow-empty-checksums -y cmake git git-lfs ninja pkgconfiglite winflexbison
+  choco install --allow-empty-checksums -y cmake git git-lfs ninja pkgconfiglite winflexbison --installargs "ADD_CMAKE_TO_PATH=System"
   $other_install = $?
   $choco_installed = $other_install -and $python_install
   if ($choco_installed) {
@@ -25,8 +25,9 @@ if (!$choco_installed) {
 
 # Add Chocolatey's native install path
 Update-SessionEnvironment
-# Python adds itself to the system environment path, which doesn't get refreshed until we start a new shell
-$env:PATH = "C:\python3;C:\python3\scripts;$env:PATH"
+# Python and CMake add themselves to the system environment path, which doesn't get refreshed
+# until we start a new shell
+$env:PATH = "C:\python3;C:\python3\scripts;C:\Program Files\CMake\bin;$env:PATH"
 
 Start-Process -NoNewWindow -Wait git -ArgumentList 'config --global core.autocrlf false'
 
@@ -52,7 +53,33 @@ Invoke-WebRequest -Uri $msvc_2019_url -OutFile C:\vs_buildtools.exe
 Get-Date
 Write-Host "Installing Visual Studio 2019"
 Start-Process -NoNewWindow -Wait C:\vs_buildtools.exe -ArgumentList '--wait --quiet --norestart --nocache --installPath C:\BuildTools --add Microsoft.VisualStudio.Workload.VCTools --add Microsoft.VisualStudio.Workload.NativeDesktop --add Microsoft.VisualStudio.Component.VC.ATL --add Microsoft.VisualStudio.Component.VC.ATLMFC --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 --add Microsoft.VisualStudio.Component.Graphics.Tools --add Microsoft.VisualStudio.Component.Windows10SDK.18362 --includeRecommended'
+if (!$?) {
+  Write-Host "Failed to install Visual Studio tools"
+  Exit 1
+}
 Remove-Item C:\vs_buildtools.exe -Force
 
+Get-Date
+Write-Host "Cloning LLVM 10.x"
+git clone -b release/10.x --depth=1 https://github.com/llvm/llvm-project llvm-project
+if (!$?) {
+  Write-Host "Failed to clone LLVM repository"
+  Exit 1
+}
+
+Get-Date
+# slightly convoluted syntax but avoids the CWD being under the PS filesystem meta-path
+$llvm_build = New-Item -ItemType Directory -Path ".\llvm-project" -Name "build"
+Push-Location -Path $llvm_build.FullName
+Write-Host "Compiling LLVM and Clang"
+cmd.exe /C 'C:\BuildTools\Common7\Tools\VsDevCmd.bat -host_arch=amd64 -arch=amd64 && cmake ../llvm -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_USE_CRT_RELEASE=MT -DCMAKE_INSTALL_PREFIX="C:\llvm-10" -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TARGETS_TO_BUILD=X86 -DLLVM_OPTIMIZED_TABLEGEN=TRUE -DLLVM_ENABLE_ASSERTIONS=TRUE -DLLVM_INCLUDE_UTILS=OFF -DLLVM_INCLUDE_RUNTIMES=OFF -DLLVM_INCLUDE_TESTS=OFF -DLLVM_INCLUDE_EXAMPLES=OFF -DLLVM_INCLUDE_GO_TESTS=OFF -DLLVM_INCLUDE_BENCHMARKS=OFF -DLLVM_BUILD_LLVM_C_DYLIB=OFF -DLLVM_ENABLE_DIA_SDK=OFF -DCLANG_BUILD_TOOLS=ON && ninja -j4 install'
+$buildstatus = $?
+Pop-Location
+Remove-Item -Recurse -Path $llvm_build
+if (!$buildstatus) {
+  Write-Host "Failed to compile LLVM"
+  Exit 1
+}
+
 Get-Date
 Write-Host "Complete"